This How To would be a good starting point: https://docs.mendix.com/howto/integration/consume-a-rest-service
**EDIT**
Based on the screen shots in your post, the JSON structure will look something like this:
{
"Picture": "https://somereallylongurlfromyourforumpost",
"Department": "RC-AR IT PTM",
"JobTitle": "Apprentice Administrative"
}
The documentation of the API you are calling should contain information about what the JSON structure should look like.
Also, the returned JSON structure is visible in your screenshots. If you want to save some typing, when you create a REST Call in Mendix, have the return value stored in a string. Then run the microflow in the debugger and you’ll be able to copy the contents of the string return value.
Here is some more info on how to work with JSON structures in Mendix: https://docs.mendix.com/refguide/json-structures