How To Edit Front Facing Activity

Hello,

I created an activity that leverages an API to perform actions within studio. One of the activities for my API takes in a set of parameters that are retrieved prior, and allows the user to alter them with this activity:

The “types” here should actually be an enum dropdown like this:

But instead it appears as a text box and I have to have the user input it in the advanced section. How can I allow the user to select the enums in the designer view and not advanced?