Michael Cera wasn’t part of his fellow ‘Barbie’ stars’ WhatsApp group chat as he has a retro flip phone.

The 35-year-old ‘Superbad’ actor plays doll Allan in Greta Gerwig’s new film about the Mattell creations, alongside Margot Robbie, 33, and Ryan Gosling, 42, as Barbie and Ken.

But he told People about not being able to join in their off-set chat: “I don’t have an iPhone myself. I have a flip phone.”

He added even if he did have a smart phone, he might not be in the chat anyway, because his character Allan “is sort of in his own little world”.

Allan is a real doll in the Barbie line-up and was first introduced by Mattel in 1964.

In the ‘Barbie’ novels, the doll started out as “Ken’s Buddy” and was romantically linked to Barbie’s best pal Margaret ‘Midge’ Hadley.

Michael added about the ‘Barbie’ film’s 39-year-old director: “Greta’s gift for me when I arrived (on set) was a picture disc of NSYNC’s ‘No Strings Attached’, which felt like somehow a real guiding light in the backstory of this character.”

Margot Robbie has given a hint of the kind of deep chat about the flick Michael may have missed.

She says she has become convinced ‘Barbie’ film tackles the concept of a power “hierarchy”.

Margot said at the European premiere of the film at Cineworld in London’s Leicester Square on 12 July: “To really do something unexpected and fun and clever and silly on such a big scale, it feels like a very unique opportunity.

“Barbieland feels like a female utopia. But you do, by the end of the film, see the flaw in that – I mean, a hierarchy in anyone's power is not necessarily the best thing. But it is fun – it’s very pretty."

The film sees Barbie’s perfect pink world of fashion, grooming and parties brought crashing down when she finds herself having dark thoughts about death.

She finds cellulite on her perfect legs and her famous feet suddenly become flat – and with the encouragement of the wise ‘Weird Barbie’ played by Kate McKinnon, 39, Barbie embarks on a journey of self-discovery in the real world, with Ken joining her for the ride.

Also at the ‘Barbie’ premiere was singer Dua Lipa, 27, who plays Mermaid Barbie in the film, and co-stars including Will Ferrell, 55, Issa Rae, 38, and Hairi Nef, 30 – who help make up the ten Barbie’s and four Ken’s in the project.