Force Toddler to Use Only One Side of Bed for Entry?

Hi all,

Does anybody know if there's a way to force a toddler to only use one side of the bed to get into it?

I made a bed and have the short protection rails only on one side because my plan was to mirror the bed and have the opening on the other side too so that way people could place it on whichever side of the room they wanted.

Any thoughts or help would be much appreciated!