Choosing Dominant 7th Chords

How do I choose dominant seventh chords? I only see major seventh.

You can use the “V/” option in the chord properties settings, as well as making it a 7th chord of course, to easily access some dominant 7ths. If the chord you’re looking for isn’t there, you can also use the chord search function, located to the right of the color-coded chords, to use any chord, including dom 7ths.