If it isn’t a property you would buy today as a rental and you can sell for a profit while taking advantage of owner occupied capital gains tax exclusion I would sell.Congrats on good 1st property purchase and the promotions! 

They maintain  no bias to promote whatever aspect of real estate they’re involved in.  

Are the promoted and built in platforms with BP pro worth it?

Don't trust YouTube promoters (people who "teach" a lot) unless you vet them.

I was offered a promotion that required me to relocate back in 2021.

You promote it as an efficiency and be clear about what is offered for a kitchen. 

What is the best way to promote it aside from listing on Zillow?

100% - AT A MINIMUM, "Flexible" cancellation is being promoted and strict cancellations are being punished.POSSIBLE - Listings that accept Pets without fees are ALSO promoted.I had 4 properties to test with.Thinking like Airbnb, I guessed the things that would make the user have the best experience is to be able to cancel and bring pets.

These law suits will start popping up in So California, Arizona, Washington, Oregon, Utah, Colorado, Florida, North Carolina, Georgia and maybe near you.Actually, the on-line training I've looked at and seen people heavily promote, is just a way to get more people to sign up for a fee, then without providing information on how to avoid this.

The market has softened and you'll likely need to join local groups and get active with promoting the property in those groups and even play matchmaker with 2-3 people looking for a room with overlapping search criteria.