In a form, what's the procedure for populating the dropdown's list of options?

I'm attempting to set up the “list of options” for a dropdown in a form. When I manually enter ABC,XYZ and run the process, I see both options listed in the dropdown, one below the other. However, I now receive the list of names (ABC, XYZ) as output from a bot, and since this list is dynamic, I'm struggling to pass this variable into the 'list of options' field as the output variable does not show up in the output section. The variable type is string, and I've set it as an output variable. What could be the issue here? Note that I have also tried to change the variable type to dictionary. The dictionary variable appears in the output section of the “List of options” but its value does not populate in the drop down when we run the process.