Inflatable hot tub (Hitchin)

Lay-z-spa (Helsinki) - pump NOT working
We’ve had this 3 years and used it each summer but when I connected the pump a few days ago the part that circulated the water isn’t working and there’s an error code.
The tub has slight discolouration, possibly from chemicals we use to clean it, but other than that it is in working order with no leaks.
Photos show the various parts and black dust on water is from recent rain and I’ll deal with this once the water is let out.