How to add password to wallet?

[Timothy Murphy]

What is the mechanism, if any, for adding a password
to KWallet?
I read the short KWallet Manager help/handbook ,
but this did not help me.

I have 3 folders in knode.
Whenever I check for posts in one of them
KWallet asks me to enter my wallet password.

When I go in KWallet Manager to knode->Passwords
I see that the other two knode folders are listed,
but not this one.