Creator: Page Parameters Help

Creator: Page Parameters Help

I need help understanding Page Parameters and making a lookup page for records specific to the lookup field. I made 1 minute video showing where I'm stuck: https://www.loom.com/share/7f905f0ec09146ad979f5d6a2a4f7051

*I've tried duplicating examples in the documentation but I'm just not quite "getting it". Thanks for your help!