How to add pre-built chords to a track

New to GarageBand looking for up to date instructions for adding pre-built chords to a track. So far all I've found on the Internet are instructions that point to things that don't exist in my Garageband v 10.4.6.

For example "click on the spanner in the upper right" but there is no spanner. Or " Select the smart option button [4 vertical bars] on the bottom left of the instrument you've chosen" but there is no smart option button there.