One of these should sort it.
https://support.microsoft.com/en-us/account-billing/how-to-cancel-your-microsoft-subscription-c2c6b0e3-cab3-cb98-d83e-c9ad54620530
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/cancel-azure-subscription
https://learn.microsoft.com/en-us/microsoft-365/commerce/subscriptions/cancel-your-subscription?view=o365-worldwide
--please don't forget to Accept as answer if the reply is helpful--