It may be that you will need to use a meter to measure fuses and voltage; i find it easier to remove the aux battery to get it out of the way, for example
a fully charged 12V aux voltage with the blue and green relays on the side (some are important to run)

There are 4 Fusible links visible behind the Positive terminal block; the 2 120A links can be seen from the top

The relay and fuse cover shows the locations (check everything in there)

The most important fuses for the EV-ECU and OBC to get powered up

If you don't find anything obviously open circuit here, then maybe the key switch contacts are frosted over and not making contact?