MacOS build is signed, but it is not notarized.
To notarize a Mac App we need apple developer account, which cost $99/years. This is very costly for us, so we don't notarize our Mac App.
Unnotarized app can run on MacOS, but it need some adjustment from you, users. Please refer to THIS complete guide to resolve issue for running the MacOS build.
If you still running into issues when trying to run the app after following that guide, please report it in the bug report post category.