Camco 55185 50amp to 30amp “dogbone” adapter
Every 50amp Rv owner should have one of these. This “dog bone” adapter will allow you to plug your 50 amp cord into the much more common 30amp plug.
When using this adapter you will need to make sure not to exceed 30 amps of power use. You should only run one air conditioner at a time and avoid using too many other high power appliances while the air conditioner is running.