Edited as I found the solution. It's an Ionic app, which runs completely well on Android. I don't own a Mac, so I'm using Macincloud. Have followed the steps for IOS and can send it, via Dropbox to macincloud and open it (after solving some issues thanks to: https://github.com/apache/cordova-ios/issues/1084 ).
But then the build failed. Below I show what I have tried.
I followed the permissions issue from https://www.educative.io/edpresso/what-is-chmod-in-windows, but it didn't solve it. I don't own a Mac, so I'm completely lost.
By following: https://ionicframework.com/docs/developing/ios the only thing I haven't done is: npm install -g ios-sim & brew install ios-deploy, because it's a Macincloud and I don't have permission to do that, and I'm not sure if that's the issue.
I also tried locking and unlocking keychain and cleaning xcode project as in Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code, but I also don't have permissions in Macincloud to unlock keychain after locking it. :(
Anyone who knows or has dealt with similar issues, I'll be endlessly grateful for your help. Thanks :)
