Steps to reproduce:
Went to the "Help" menu and chose "Send Feedback". Since I didn't have an account, I clicked on the "Sign Up" link. I'm offered the ability to sign in with a bunch of services that track me everywhere on the web such as Google and Twitter, but no option to sign in with Apple.
Sign in with Apple should be an option for sending feedback on Orion.
Orion, OS version; hardware type:
Version 0.99.113-beta (WebKit 613.1.12)