Merging IDs or transferring data

I have two Apple IDs, one of which is linked to an email address that hasn't existed for nearly two decades. This means that I cannot receive 2-factor authentication emails related to this address. I would like to merge it with my more contemporary ID, or barring that, transfer its licenses etc to the contemporary one. How can I go about doing this? The way things stand I have to regularly sign in and out of a variety of IDs to keep my various apps and such updated. Thanks.