I can't find the switch to the door and using the key to open it isn't working.
It's a first generation van.

it is open from under the driver seat ,if it does not open have somebody pull the lever and u open it . if thats the case the spring is broken ,dealer i put a paper clip on mine the one that you squeeze to open lol (small) get the idea from a friend

same happened to me. I put a small spring using one of the screws that was already there.

There should be a small yellow lever under the front right corner of the drivers seat