Below is link to supposed official MS work-around if standard activation attempts for Office 2010 fail. Note the 866 toll free number.
I don't know if it will help, but worth an attempt?
https://support.microsoft.com/en-us/office/-telephone-activation-is-no-longer-supported-for-your-product-error-when-activating-office-9b016cd2-0811-4cb3-b896-5a6a13177713
866-421-7141
I also found the following comment from someone who apparently used that 866 number very recently:
https://borncity.com/win/2021/07/29/microsoft-office-2010-keine-aktivierung-mehr/#comment-15549
"This did work for me. The process was a little long but it ended up working. I called the number given at the website (I'm in the USA). When I called the number I got a computer asking me through some prompts. It asked if it could send me a text with instructions. I did so, but the text instructions did not work. However, the text instructions offered to connect me a representative. I chose that option and got a live person. I was able to read off the 9 block x 6 digit activation ID to him, and he responded with an 8 block x 6 digit code, which successfully activated my product. The writer above said that when he called a person, Microsoft said that there were no circumstances that would allow them to activate Office 2010, but the person he was talking to was incorrect, because my representative was actually able to do it. He was aware this was Office 2010 and it didn't cause any problems."