What you are describing would be accomplished with a Hand-Off-Auto (HOA) Switch.
Hand = Manual Mode, Local Control
Off = Off
Auto = Photon Mode, Remote Control
You can use a Relay on the Board to switch 12V On/Off to the SSR while in Auto Mode.
Google HOA Wiring and you will find lots of diagrams.
Here’s an example..
The Goal is for anyone to be able to follow the wiring in the Field. Driving the SSR via a Digital Pin directly is not as obvious as using the Relay in the Automatic Circuit.
Is it “better” to use a relay to drive an SSR in this situation or is the digital pin sufficient? Assuming that is, that I choose not to use a relay board.
If you decide not to use the relay board, you can still add a cheap 1 channel relay “in-line” in the “Automatic” Circuit for the Digital Pin to control.
That way, you are using 12V to operate the SSR on both Manual and Automatic modes.
I’m not an electrician or a EE. But in my mind, the Switching for the Auto Mode should happen “downstream” of the HOA selector. I.E. the HOA will send 12V to either the Manual circuit, or the Auto circuit. Your photon controls a relay just before the SSR to switch that 12V on/off, when the HOA is in Auto Mode.