My Apple ID email is different to the email appearing against subscriptions; how do I change the email in subscriptions to be the same as my Apple ID?
iPhone 11 Pro
Cancel the existing subscriptions and then take out a new subscription using your current Apple ID.
You are sign in here . . . with your Apple ID & Password (?).
Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.
You can’t merge multiple Apple ID accounts.
See this Apple article: Change your Apple ID
Change your Apple ID - Apple Support (SG)
Then see this Apple article: What to do after you change your Apple ID or password
What to do after you change your Apple ID or password - Apple Support
how do I change the email in subscriptions to be the same as my Apple ID?
You cannot change for example) from your 2nd Apple ID to your 1st Apple ID.
Because the 1st Apple ID is in use, yes . . . . by yourself.
Otherwise change from 1st to 2nd will not work either.
ID email different to Subscriptions email; how to change
