It's the Wrong headphone Gromit!

[DavidEdwinAston]

I don't have a dongle at the mo' Jimbo. The One plus actually has a 3.5 mm audio output. USB C for charging, of course.

 

[DavidEdwinAston]

So, on the bus into Walton, noticed "Treasures mobile phones".
Showed the guy my phone and the Moondrop Chu's. He looked at the 3.5 mm jack. Produced an Apple/Ugreen type connector, and sweet music resulted!
A brand called kit:, £14.99.
Thank you all so much