How do I change the length of a beam through blueprint?

I am trying to change the length of a particle system’s beam in a blueprint and I have tried using the set beam target point and the set beam end point but neither of them seem to be affecting anything. My particle system only has one emitter and one beam so I’m leaving the emitter and target index at 0. Is there someway I can set up a particle parameter for this or am I using these functions wrong?

I’ve tried using the beam modifier as well but that does not seem to change my ability to change the beam via blueprint. It can change where the beam is going but only to preset locations in the beam modifier. So that means still no blueprint control. Is there any good documentation on this?

You have the beam method in the drop down set to target? I am trying to do this from memory as I don’t have the editor and my working beam example in front of me…but I believe you also need to add a Target and Source module, and make sure they are set to userSet and give them names of Target and Source.