Thanks for reaching out with a picture of your thermostat wiring. I'm happy to help.
Based on the diagram, it should be compatible with the Nest thermostat. Follow these wiring configurations:
Then, when you reach the part of the "Which wires do you have?" set-up process, select the same configurations as above. Here's your guide adding it to the Google Home App.
Let us know how it goes.
I just want to check if you have seen our response posted above. Let us know if you have additional questions, otherwise we'll be locking the thread in 24 hours.