I hope your HA is better than mine. I was told I couldn’t have one as they didn’t have a policy on EV chargers. My MP was furious and tore them a new one didn’t change anything so I just opted to go-ahead and not tell them.
If you don’t have a 100A fuse you could contact the DNO and get that happening whilst you’re awaiting stuff from the others. I needed a fuse upgrade as mine was 60A and a new incomer as mine was looped with next door. I managed to get all that in motion whilst Motability and BP were not fitting my charger lol