I am a newbie with same message - found this while searching for a resolution. Apple says I don't have to enroll in the developer program (with $98.99 annual fee) just to build iOS (in my case MacOS) app for personal use - that is, not for distribution via the AppStore. Of course, Apple didn't have in mind me using flutter - and I'm just following some one else here with a GitHub clone of a cross platform program which I hope to learn enough - if it is possible , will figure that out later - to build for niche platform (Raspberry pi) - which the lead developer says is not a priority - though I am not the only one interested and would help me out too.