What you have is a Nema 6-20 plug and the Receptacle is a nema 6-20r and they are compatible and both rated for 20amps 250 volts. BUT BUT BUT is this the amperage and voltage the mini split calls for, and is this also the amperage and voltage supplied to the receptacle?

Who put the plug on? The plastic shield needs to be under the white grip of the plug and not the wires. Until you tell us the Mini split amperage requirements and the receptacle supply voltage, wire size feeding the receptacle and breaker size I won't tell you to plug it in.

20A will have 12 gauge wires and a 20 amp two pole breaker so check before plugging.

Thanks kevin heres some more info… i know the hot tib 220 works fine.

No problem with voltage supply. Looks like the photo shows 60A 240V rating for the hot tub. Check and see the amperage of your hot tub circuit breaker inside the house electrical panel if it is 60A breaker. 60A should be more than needed to run the mini split.

If Field installing a cord connect to an item only UL rated for direct wire should never be done.

I would check the installation manual to see if it is allowed to plug in. They can be plugged in 220v, but your current receptacle is rated for 20A which may be not enough to run your mini split.

What did the installer of the mini split say?

My bet is that this is a DIY project.