The “True Detective” star, who first made her name in the boxing ring, isn’t scared of online trolling — even by the creator of her show.

Two days after the finale of HBO’s “True Detective: Night Country,” Kali Reis was rolling hand wraps, alone, inside a training center on a farm in northern New Jersey.

Before she was ever cast in the anthology series as Evangeline Navarro, a steely Alaska state trooper; before she walked red carpets in London, Paris and Los Angeles; before she ate Christmas dinner at her co-star Jodie Foster’s house, Ms. Reis was a champion boxer. Her most recent bout, though, was fought online.

The night before, Nic Pizzolatto, the creator of “True Detective,” had reposted a series of fan complaints about the finale on Instagram, apparently in an effort to distance himself from the show’s just-concluded fourth season — the first that he hadn’t written.

Ms. Reis, 37, is familiar with trash talk, online haters and naysayers. “Boxing is a beautiful craft, but it’s brutal,” she said, adding, “Everybody’s got an opinion.” The same goes for acting, she has found, especially since the show’s finale aired. In her experience, there’s always that one “dedicated troll,” she laughed.

Ms. Reis (pronounced reece) quickly snapped back in her own late-night post, calling Mr. Pizzolatto’s comments “a damn shame.” According to HBO, her season of “True Detective” drew 12.7 million viewers across various platforms — more than any of the show’s previous three seasons. A few days after the finale, the network renewed the series for another season, with the new showrunner expected to return. (Through a representative, Mr. Pizzolatto declined to comment for this article.)

Ms. Reis, right, and her co-star Jodie Foster, in a scene from “True Detective: Night Country.”Credit…HBO
Not only in the ring and onscreen, Ms. Reis says she has always “had to prove who I was and who I wasn’t.” She is of both Cape Verdean and Seaconke Wampanoag descent, and she knows how easily some will impose on her identity what they want to see and look past what they don’t.

“They’d say, ‘Well, you don’t really look Indian,’” she recalled. “And I’d think, ‘What the [expletive] am I supposed to look like?” Her tough exterior is a function of a lifetime of criticism — and not only from others: “There’s nothing anyone can say to me that I haven’t already said to myself.”

Ms. Reis in January at a “True Detective: Night Country” premiere in Mexico City.Credit…Hector Vivas/Getty Images
On a recent Tuesday at the New Jersey training center managed by her husband, gloves, shoes and gear piled out of Ms. Reis’s purplish-pink suitcase on the outer edge of a boxing ring. Fluorescent lights glared overhead. Punching bags hovered in the distance. Air-conditioners roared.

At a folding table at the foot of the boxing ring, she was open and warm, dressed in a colorful, short-sleeved shirt. Her appearance was notably at odds with the muted parka and woolly hat she often wore on the show, a bit like seeing your elementary-school teacher at the beach. Everything else — the piercings, the tattoos — was all there.

What comes next for Ms. Reis is uncertain. Later this month, she will appear in “Asphalt City,” a paramedic drama starring Sean Penn, and she has finished shooting for the movie “Wind River: Rising.”

“There’s nothing anyone can say to me that I haven’t already said to myself,” Ms. Reis said.Credit…HoJun Yu for The New York Times
What has changed for her since starring in an HBO show? For starters, her neighbors finally know her name. “And the ‘House of the Dragon’ cast does, too!” she added. Zahn McClarnon, an Indigenous actor best known for “Fargo” and “Dark Winds,” has reached out, and Ms. Reis said she was eager to cross paths with a fellow Native actress on the rise. “I can’t wait to meet Lily Gladstone,” she said.

Despite the taste of HBO fame, Ms. Reis has no plans to change: Authenticity is nonnegotiable with her. “On the red carpet, you’re supposed to wear Gucci, and I’m like: ‘Listen, I don’t wear heels. I wear all black,’” she said.

In Ms. Reis’s childhood neighborhood — which she described as “neither good nor bad” — she was “the token Native kid, with thick Harry Potter glasses and braid ties.” Other children picked on her, sometimes calling her Pocahontas.

Growing up, there were signs of a future career in acting. As a child, she dressed up in her mother’s clothes and performed one-person plays, with protagonists inspired by the people she met on the streets of East Providence, R.I., her hometown. One character in particular, Mary, was “based on the older ladies who smoked Newport 100s and drank Dunkin’ Donuts all day.”

“How ya doin’, darlin’? Got any ciga’ettes?” she croaked in a gravelly Rhode Island accent.

“I’d love to do comedy,” Ms. Reis said. “It’s always been a dream to be on ‘Saturday Night Live.’”

She believes the roots of her attraction to comedy run several generations deep. “In my Indigenous community, we love to tell stories and crack jokes on each other,” Ms. Reis said. “Laughter is what’s gotten a lot of us through” some tough times, she added, using more colorful language.

After taking some questions by the ring, Ms. Reis started to put on her gear. “I’m going to teach you how to tie boxing gloves,” she said, putting a half-laced one in front of me. I tugged hard on the strings, as directed. “Tighter,” she said several times. “Is that how you tie your shoes? You need Velcros, bro!”

While Ms. Reis has laced up countless times, her acting career is still very much in its first round. She has played several Indigenous characters — including a half Native, half Cape Verdean boxer in “Catch the Fair One” — but says she is planning to spread her wings with future other roles. “I’m an actor,” Ms. Reis said with a pause, then smiled. “That’s so weird to say.”

Still, Reis is interested in expanding the scope of Indigenous representation and interests. “What if we want to tell a happy story, or a superhero story?” she said. “I’d love to play a villain.”

No matter what path her career takes, Ms. Reis doesn’t plan to pull any punches saying what she wants to say, “how I want to say it.”

“I’m not going to worry about who signs my checks,” she said.