plumbing basics - hose connector

I feel a bit daft, but hopefully someplace can help me

Recently I got a hot tub installed, and it has a drainage tap that is clearly marked 1" ball valve with a threaded female connector. I want to attach a hose so I can drain it away from the tub a bit - should be easy enough I thought.

So I logged in to Screwfix and purchased a 1" to 3/4", male to male, coupler (https://www.screwfix.ie/p/midbrass-brass-compression-reducing-coupler-1-x-3-4/455hp), thinking I could screw the 1" end into the ball valve connector. I also bought a 3/4" hose connector (https://www.screwfix.ie/p/hozelock-1-2-3-4-threaded-tap-connector/52973) assuming I could screw this onto the 3/4" end & hence connect a hose.

Collected them & brought them home, only to find the 1" end is slightly too large to connect to the 1" ball valve connector and the 3/4" end is slightly too large to connect to the 3/4" hose connector.

Clearly I have done something wrong, but I don't know what. While it has only cost me a few quid, I don't want to keep going with trial & error.

So can anyone help this eejit and maybe point to exactly what I should be using?

Update: Duh! I've realised why the coupler was wrong, its a compression joint for attaching a 1" pipe to a 3/4" pipe, not something that will screw into a 1" female threaded connector. So I know what I did wrong, I just don't know how to do it right … so help still sought.