You're gonna need a wider enclosure. You have very big wire bending space problems in this one. It's pushing the breaker out of position and that's going to cause bad contact at the bus stabs, and arcing and bus burn-up. A sad waste of a $150 breaker. That enclosure is only about 5-3/4" wide on the interior: too narrow for those fat wires.
Given that breaker, stay Siemens. I was really hoping to find you a vertical-oriented Siemens 6-space, but I can't find such a thing. So your next step up is a (Siemens style) 8 or more space panel, which are a full 14-1/2" wide (but that gives you 7" of width per breaker, so that takes care of the bending space problem).
Also, those wires are totally unmarked. You're not allowed to use "mystery meat" wires. I'm seeing where this is going into a conduit, and in conduit or inside a panel, 8 AWG copper is sufficient for 50A. If you could change to a marked #8 wire, that will probably relieve the bending space problem here.
Once that is resolved, you seem to have 2 additional spaces to accommodate 2 breakers or one 2-pole, or tandems or quads up to 4 "circuits". Don't forget GFCI protection, and it's better if that is at the source (i.e. breaker or right past the breaker). 120V power near a hot tub is dangerous.
Also note it is illegal to have even a GFCI outlet within 6' of a hot tub. Also what on earth does an Echo Dot need 120 volts for? Checking, I see it actually runs on USB power. Long USB cord and Bob's your uncle. Maybe don't invite your friend to hot tub anymore since they seem to be trying to kill you lol.
Also, get rid of the tape on that wire nut. If you don't trust it to hold together without tape, it's not nearly tight enough, and it's going to arc and overheat. Wire nuts need to be VERY tight.