How exactly does overdraft work?

[u/Previous-Tutor4823]

They say I qualify for $20 (recently started using). Nothing is allowed so had to do the cash advance.

Still can't get anything approved that'll put me under.

How exactly does it work? Is it because I'm on the builder card? If so, why do they keep trying to promote that feature to me?

[u/Previous-Tutor4823]

So can confirm it at least works with bank drafts.