
In the film, one of the key scenes centres around Pride celebrations in the fictional English town of Truham, where the Heartstopper universe is set.
Connor says it is important for audiences to witness this on-screen representation, "wherever we are in the world and whatever the powers that be are doing".
He adds that "making a show or film like Heartstopper will forever be important".
Netflix has confirmed through its media site that the film will be available in several territories where homosexuality is criminalised.
The 22-year-old, who rose to fame in the TV adaptation of His Dark Materials, also had a key role in Elton John biopic Rocketman.
He says he was forced to come out as bisexual, after social media speculation, when Heartstopper's first series was released in 2022.
"Heartstopper in its very existence has [always] been this beautiful and powerful message about queer joy and humanity," Connor continues.
"These characters happen to be queer and incredibly happy about it, living their lives in the way they want to," he adds.
The final instalment of the Heartstopper saga was originally set to be released as a fourth series, but despite a shorter running time, each individual's storyline is still handled with care.
The film explores conversations around eating disorders, mental health, alcohol dependency and difficult family dynamics.
Locke and Connor are also both producers for this final chapter, which Connor says allowed them to "be the creative input and mouthpiece for the cast" who "all care about these characters and the story".
Locke, 22, jokes that a lot of the time people are just handed producer credits, but clarifies "we actually put some effort in and took it seriously".
There is some sadness though at saying goodbye to each other in a professional sense, with Locke noting that the show has "changed my life in pretty much every way".
"It's the biggest thing that will ever happen to any of us," Connor adds.
"I value Joe as a friend, if we work together again that's great but he's a great actor and I love watching his work," he says.

