Microsoft 365 Excel workbook charging for edits

If you have an Microsoft365 subscription, then you shouldn't be charged, so the problem is likely an account/login issue. Is this a shared workbook that was shared to the account you use with your Microsoft ID or to a different email?

Maybe you're subscribed under one Microsoft ID, but are logged in using a different one (or not logged in at all)

https://support.microsoft.com/en-us/office/microsoft-365-customer-service-and-support-96162163-b3aa-498b-bbbb-5e757b0f31da