Most likely you have a dometic 13500 btu ac. If you can get the model & serial numbers off of it someone here will likely have the manual or you can find the manual online.
A 2000 watt generator is probably right on the edge of being able to run that AC. So maybe. And as long as nothing else is running. The biggest load will be when the compressor starts up, you can reduce that by installing an AC hard start capacitor kit similar to this: https://www.rvpartscountry.com/Domet...Capacitor.html
A 3000 watt generator should run your AC just fine. I run mine on a Honda 3000 with no issues. Runs the AC & lights, TV at the same time just fine. I shut off the AC to run the microwave though.