does someone know where the primer is?
You will not find one because the Arrow III is equipped with a fuel-injected Lycoming engine.
what he said.
the tablet however has a red warning with “priming required” if I remember correctly.
Mixture fully rich, fuel tank selected, fuel pump on until you see the fuel pressure gauge jump to (5?)
The Arrow III does not have a primer. However, some fuel injected airplanes DO have primers. The Turbo Arrow IV does have a primer. When pressed, it opens a diverter valve, operates the fuel pump on HI, and supplies fuel to two primer nozzles. Cessna 404s and 421s also have primers and they are very fuel injected. All of those airplanes have Continental engines but the Arrow III is a Lycoming.
As a general info: The JF PA28R comes with a comprehensive manual which is updated together with the addon.
There you’ll also find a section on how to prime the engine and much more.
Take your time to read it, it’s pretty interesting.