You have not sold for a really long time (if at all) so you will need to add a bank account to your Ebay account to receive payments.
Use 'help & contact' top left of your Ebay page for useful information.
If you use 'add a bank account' as the search term you will find the link you need.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)