How to recover iCloud account without access to old phone number?

I have a different phone with a different iCloud email and the phone I have attached to that account is not activated or mine anymore. Is there any other way I can get my account back since it’s asking for the old number for a code for verification but I don’t use that number anymore. I know the number but I have no way of contacting it.

[Re-Titled by Moderator]