With foot hard on the break pedal and handbrake on then I’ve held the key in start while Running the gear selector up and down - there’s no responseOK so try the first bit, running the gear selector up and down while holding it in start. If you don't get engine turn over then you need to test you have power arriving at the starter solenoid on a violet or violet/white wire. If you have power there then that just leaves an earth bond strap broken or a break in the main live feed from the battery to the motor (unlikely) or ultimately the starter unit itself. Money is on the inhibitor switch or wiring from it.