Starfinder 2e - How do I add a second damage type to a weapon?

My friends are experimenting with moving from Roll20 to Foundry VTT. For my character, I have a weapon that does 1d10 + strength bludgeoning damage AND 1/2 my level in fire damage (currently 3 fire). The only additional damage types the default weapons allow is persistent or splash damage, which this isn't. I cannot for the life of me find a way to add a custom damage formula or additional damage values.

I also tried creating a macro just to skip the weapons that come from the starfinder module entirely, but I have no clue how to make it reference my attack bonuses or ability modifiers. In roll20, you could just see a list of attributes and use them directly in the macro, but every tutorial I've looked up is saying things like you have to like dig in the f12 menu console just to have a chance of finding the right thing? Why does it have to be so obtuse?