Ask for a little step ladder you can put in your cab or you can bungie tie to the back of your unit?
I’ve never had this issue. Sometimes you can stand on the bar below the brake lights or just stand on the lights themselves.
Either that or a good run up. Ask the forklift driver to give you a lift up.
Many ways to get up.
That being said. Put the ball in the employers court if you dont like it. If they refuse get it in writing. Wait a month. ‘Fall by mistake’. Then take them to the cleaners.