First, you have an Office 2019 Pro Plus version activated. Second, the point Ron B is making is that Pro Plus, wether it is 2019 or 2021, is not a legitimate version you can buy retail. So if you bought it on the internet, especially at a severely discounted price (like under $100) it is a bootleg license.
How did you get Pro Plus? If you got it through the HUP, Home Use Program, from your work, fine. If you bought it off the internet (probably for less than $100), it is 99.44% likely to be an illegally resold "volume" license. You stand the risk of MS becoming aware of what the vendor is doing then MS will disable the keys and you will be out of u8MAn1.