Greetings!
This is Tin, I understand that you would like to cancel your subscription as you're planning to transfer to different one.
You may sign in to https://account.microsoft.com/services and check all of your account regarding the subscription. Once you've found the account, you'll have an option there to manage and cancel your subscription.
For your reference: https://support.microsoft.com/en-us/office/cancel-a-microsoft-365-subscription-46e2634c-c64b-4c65-94b9-2cc9c960e91b
Please let me know if you have any questions.
Thanks,
Tin