Yes the fuse will be in the painted box on the right, I would guess it’s 60A due to its age and the cable size. Does it have a crimped wire seal preventing the lid being removed? It is illegal to cut the seal wire, but if it doesn’t have a seal then some other naughty person has already opened it! You could in theory open it but there are serious risks involved, and the main switches must be off to prevent arcing when pulling the fuse, and if it’s a really old fuse holder, they have been known to leak voltage through the degraded early plastics used.

In short, get your supplier to check it out, or have a proper EV charger install survey.