Unable to install "SitnuWatch WatchKit App"

[BassJonathan]

WatchKit app can not be installed on AppleWatch.

Following issue:
The executable was signed with invalid entitlements.
Domain: com.apple.dtdevicekit
Code: -402620394
Failure Reason: The entitlements specified in your application’s Code Signing Entitlements file are invalid, not permitted, or do not match those specified in your provisioning profile. (0xE8008016).

Tested with:
iPhone 6s with iOS 13.2.3
AppleWatch 4 44mm WatchOS 6.1

[TheNoim]

You probably just downloaded the SitnuWatch-v1.3.3 ipa. You can't just do this. There are two options: Building the project with xcode or you need to use the ipa. However, if you use the ipa, you need to sign it first. For this you need an apple developer account and some software like cydia impactor.