What to do with rank math after domain migration

I’ve migrated from and old domain to a new one. My new host provider did the migration for me using their official migration plugin.

After that, I went to my old host provider, and configured redirection to the new domain using the “redirection” function that comes with CPanel, where I just needed to select the old domain name and type in the new domain and hit save, and Cpanel wrote the redirection rules to my htaccess file for me.

Then I went to Google Search Console and used the ‘Change of Address’ tool to notify Google about my bew domain.

Then I went back to my new host provider. I disconnected and reconnect my new domain to the rank math plugin, as suggested in this link: https://support.rankmath.com/ticket/domain-name-2/

So my question is, do I have to go to my old host provider, and reconnect rank math plugin with my old domain? Or should I disconnect the plugin from the old domain so that Google won’t be confused between the the old and new domain? (Both domains contains the exact same article and content )

Do I even have to set the canonical URL using rank math to point to the new domain addresses on my old domain, one article by another? i have hundreds of articles on he old domain and this will kill me.

Or do I have to disable rank math on my old domain? I’m don’t know if this will kill my SEO score on my new domain.