The creators of the pocket want to make that token effort of not being associated with piracy so have taken some minimal steps to make sure that you cannot load roms. But they have also partnered with GB Studio to make a workaround with games created with GB Studio. So here we are.
Hello,
I created a fork a GB Studio 2 that export natively game in pocket file.
https://github.com/BestPig/gb-studio#analogue-pocket-export
I don't know if migrating a game from 1.0 to 2.0 breaks stuff, so maybe only works for game made with the 2.0. If you have any issue with it, don't hesitate to contact me.