How to check Office 2021 product key in My Personal Account

[robolab]

I purchased "Office 2021 Home & Business PKC" to manage product keys for my small business.
I created an @outlook account in my company's name and registered the product, but I can't find which product keys I'm using and which I'm not, or how to retrieve the product keys I'm using.
Please help.

[#2]

This is still open. Please help.

[#3]

@robolab 

What type of product are you using, M365? If yes, it can check from Admin portal

[#4]

I'm using Office 2021 with a perpetual license, not a subscription. I have physical key cards, but I can't see who is using which key because I manage them in one account.