How to delete account in https://forum.phalcon.io/?
I'm not sure you can delete the record that forum.phalcon.io has for you. You can revoke access though.
In Github, go to your settings, then down to Applications, then click on the "Authorized OAuth Apps". You can revoke access to the forum there.
Why do you want to delete your account?
That sad :( that you want to leave this community !