How to build flutter iOS app without AppStore

I made an app for me and my friends and I don't intend on publishing it on the app store, it's easy to build the apk file for android and send it to them but some have iPhones. Is it possible to build the IPA without an apple dev account, macOS and all those certificates?

I would install it with cydia impactor and renting a mac server to do the build is no problem.I read the post on flutter.dev but it's overwhelming for what I want to do.

Solution

It's possible to create an unsigned iOS .ipa without code signing or Apple Developer account.

Run the Flutter app first to an iOS simulator to generate iOS build on /build/ios.
Create a folder anywhere you like with the name Payload - note that this is case sensitive.
Navigate to /build/ios/iphonesimulator and copy Runner.app to the Payload folder you've created.
Compress the Payload folder with default .zip format
Rename Payload.zip to Payload.ipa