From my teen years (way back last millenium) when I worked for a propane outlet most NG appliances can be converted with a simple conversion kit. I have seen Lincoln 1116 ovens that are NG converted to propane and the Lincoln 1117 which is a propaane oven converted to NG. The manufacture’s web site is a good place to look for a conversion kit.
Most all gas ovens can operate on propane or natural gas.
Just a matter of an orifice in most instances and often also a spring in a gas valve.
Most any service company should be able to make the change.
George Mills