Hello,
There may be an issue with your current Microsoft account.
If possible, try creating a new Microsoft account (for example, one ending in @outlook.jp).
create a new Microsoft account
When contacting support, explain that you're unable to submit a Microsoft Rewards support request using your original account, and try submitting the request using the new account instead.
If you're still unable to submit a request, there may be a temporary issue with the Microsoft Rewards support system.
In that case, please wait a day or two and try again.