Zoho Deluge (Creator App)

Zoho Deluge (Creator App)

I need help understanding how to automatically populate and add rows to a subform. I'm using a dropdown field as the "trigger". I made a 1 minute video hopefully someone can point me in the right direction? Thanks for your help and time. Chris
https://www.loom.com/share/046f548e69094ae5a12596b7d4642fc9