Slider fixture in simulation

Hello,

For one of my projects I'm doing a stress analysis on a pull up bar. I have modelled it but can't seem to add the correct fixtures. So far I have added the fixed fixtures on the bottom face of the top of the tubes, this replicates the bars sitting on the top of the door frame. I have added a load which you can see in purple. For the last constraints I can't seem to add a slider fixture that can only move on the y axis. I want it so that it can replicate it pushing against the door frame when a load is added.

Thanks,

Lucas

SolidworksSimulation