Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Greetings!
This is Tin, just to confirm, you have used or associated your license to your Yahoo account and you would like to transfer it to your Gmail account. Is that correct?
To check, please sign in to https://account.microsoft.com/services and check which account have the license.
Also, if you accidentally used the Yahoo account for your MS Office 365, you will be needing to cancel the subscription and resubscribe using your Gmail. Because I'm afraid there's no way to transfer it directly.
If you have MS Office 365 Family, the good news is you can just share the license to your Gmail account. To do that, please visit the link below:
Please let me know if you have any questions.
Thanks,
Tin