saving brushes

I just upgraded from Elements 2018to 2021, and having a nightmare getting my new brushes to stay in the file, they keep disappearing. Reading support pages and makes me even more confused.  Also, how do you import your brushes from 18 to new 2021.  Sorry I bought this upgrade - I have hundres of brushes I use!

Moved from Using the Community (which is about the forums) to a better forum... Mod
To find a forum for your program please start at https://community.adobe.com/