How do I pass a variable that I created for a Grafana Dashboard as a body parameter for a JSON Query of a Grafana Visual?

Question

I am using the Grafana Infinity Plugin to make GET/POST requests to get data from the URL of an API for a visualization on a dashboard.

For a particular POST request, it takes an input parameter called location_id. The possible values that can be passed for this parameter can be obtained from another GET request.

I created a variable in the grafana dashboard that has contains of those possible values as a GET Request, and it appears as a drop down on my dashboard that allows me to select one of the values. I want to make it so that when I select a value from the drop down, the previously mentioned POST request will take that value as an input parameter. How do I achieve this?

Here is the dropdown variable with possible values I could pass in the parameter:

This is the post request requiring the input parameter. Currently I have to hardcode the paramater, but I want to replace it with the variable name of the dropdown

Basically, when I select a new value from the drop down, I want to pass that as the new input parameter for the API call. Would appreciate help on how to do this.