Yep, that's all you need.
The dynamic buttons are the same on G20-G23's. Only difference is if they are edge lit or non edge lit. Those are non edge lit, and in the pics you posted your buttons are also non edge lit buttons. So those are the ones.
Just be sure when replacing buttons that you don't touch anything with the power on. lol I unplug it completely myself when swapping buttons.
But with replacement buttons, you just flip over the button deck, carefully pop off the ribbon cable that goes to the buttons you are replacing. Remove the plastic nut from the back of each button to replace and they slip out the top of the button panel, and put the replacements in and put the plastic nut back on (snug, but not super tight, just enough so they don't move around). Then "carefully" reattach the ribbon cable to the buttons, ensuring that the ribbon cable connectors are secured on each button in the panel.
Then close up the machine, making sure no wires get pinched under the button deck when you flip it back over, power on, and the replacement buttons should be lit up again just like your other ones. Those buttons aren't "brand new", but they're servicable. And will likely match the brightness of the buttons you have that still display ok. Considering the price of new buttons, it's the cheapest way to at least get all the buttons lit up again.