Is it safe to buy a key from a website?

I bought an avast key, when I use it, it’s a key for 10 devices. Want to know the owner who bought the key? Can he do anything with a machine that uses this key?

Bought the key from Whom and from Where?

I bought from G2A website.

https://www.reddit.com/r/pcgaming/comments/aqhdfb/is_g2a_a_legit_site/

Note: https://support.avast.com/en-ww/article/26/