It would help to know what you’re trying to accomplish. It looks like from your code that you want to send two values to your device. Is that correct? I’m not sure you would need a list to do that. I think something like this, where you combine the two values, should work.
This could be simplified quite a bit to the following that doesn’t use any global variables
These would send the two values separated by a comma, which you could then separate in your device code. You would need to change tempValues in the /tempValues?access_token= string to whatever the name of your Particle.function is.