It is most likely a 240vac outlet.
RV use 120vac on two separate legs.
Have an electrician put in a NEMA 14-50r receptacle. Make sure he has insurance AND that he knows the difference specifically for an RV receptacle versus a dryer 240vac receptacle.
If he does it wrong (has been known to happen) he will fry all your electronics.
Have him read the article below before he starts just to be sure.
RV electrical wiring.
RVs use 50 amp NEMA 14-50r outlet, BUT they use two 120v legs. NOT 240v.
Very good article explaining this.
https://www.rvtravel.com/rv-electric...p-shore-power/
Also...
https://www.rvtravel.com/can-i-use-a...-amp-rv-power/
Other useful link.
http://www.myrv.us/electric/
Also...
https://www.keystonerv.com/upper-nav...rical-systems/
This explains it all
http://www.myrv.us/electric/Pg/50amp_Service.htm
Depending on where you live, having a generator for a back up to power outages is not a bad idea. Also if you go boondocking, you will want a generator. Just make sure you buy an inverter generator. They are much quieter than an open frame generator. You, and your neighbors, will appreciate the noise difference.