2013 Hyundai Equus - Keyless malfunction

Truck won’t open. Just with key

I would first check if there is a separate fuse for the trunk latch. probably not but it is worth a look. it is probably a bad lock actuator that needs to be replaced.

The battery in your key fob may be dead or dying. Or the fob itself could have an issue.

I’d check the key fob battery first, possibly go ahead and just replace it.