Based on a book series by Rachel Cohn and David Levithan, the holiday rom-com show — which is now streaming — follows New York teens Dash (Austin Abrams, “Euphoria”) and Lily (Midori Francis, “Gotham”) as they get to know each other via a written correspondence in a notebook.

Lily initially leaves it on the shelf of iconic bookstore the Strand, in hopes of sparking a romance with a like-minded book nerd. It doesn’t work out quite how she anticipated, since Dash is grumpy where she’s quirky and cheerful. But like all classic rom-coms, opposites attract.

Now, how do the Jonas Brothers play into this? (Spoilers for the end of “Dash & Lily” ahead.)

In the final stretch of the show, Dash and Lily finally meet in person after their long written correspondence — but things go awry. Frantic to fix it, cynical Dash runs to meet his friend Boomer (Dante Brown), who happens to be at a Jonas Brothers concert for New Year’s.

The camera cuts to the three brothers there in the flesh: Nick, 28, Joe, 31, and Kevin, 33. They’re playing Christmas tunes on an outdoor stage at Hudson Yards.

Later, Dash, Boomer and some of their other pals find a quiet place to talk about how Dash is going to win over Lily. They’re interrupted by Nick Jonas, because it turns out this “quiet place” is his trailer.

“You need to go to her . . . your friends are right,” Nick tells Dash, after listening to his tale of romantic woe. “If you want this girl to give you a second chance, you’ve got to get real. Also, why are you in my trailer?”

Within the world of the “Dash & Lily” story, it turns out that Nick went to band camp with Dash’s friends who are in a Jewish punk band (which is how they have access to his trailer). Outside of the plot, Nick is an executive producer of the show.

Nick continues his romantic pep talk by saying. “When I proposed, I had to dig deep, I had to get vulnerable.”

Dash points to him and says, “That’s good. That’s really good. Alright, we’ve got to go!”

“I wasn’t done with my story though,” says a confused Nick.

Dash gives him a hug before running out of the trailer. “No, you were perfect. You were great. Thank you, Nick Jonas!”

The real-life experience was just as thrilling, Abrams said.

“It was great, I got to meet all the brothers,” Abrams told The Post in a recent interview about the show. “They’re all really nice guys.”

“Dash & Lily” is now available to stream on Netflix.