I have defined a Managed Result Source at the Search Application level of my SharePoint Online tenant and am attempting to run this search using the /_api/search/query REST endpoint. I know this search result works because I am using it well on my sites using the Query Results web parts which are configured using this same Result Source. I captured the ID of my Result source from the URL.
I then place that ID in the following REST URL in Fiddler
The JSON returned is a not a list of the specific content types which I am searching for.
Do I need to add more to the REST query to get it to behave like the Search Results Web Parts do?