Cant get into account because of 2 factor authentication using an old phone number

I cant access my main apple ID (the one I'm posting with is a very old one, the only way I could post here). After most recent IOS update, I kept getting notifications to sign back in. However when I sign in, it wants to verify by sending me an auth code, but the problem is, the code is getting sent to an old number I no longer have access to. When I got my new phone and new number, I DID have access temporarily to the old number - I think this is how I signed in originally, and must not have changed the number (I thought I did but guess not). My new phone is an iPhone SE if that even matters...

So I attempted to sign in online, following some instructions I found here to update the phone number but of course though to sign in with this device too, it wants an authentication code, also sent to this old number.

What is a workaround this? I bet whoever has my current phone number is getting ****** at all these random codes texting their phone.

Is the best solution to just create a completely brand new apple ID?