Creating assignment with API (Pre-filling GPS question produces error)

I’m using the REST API for creating assignments.

When trying to assign values to a GPS questions that is the questionnaire cover. When executing a POST over the end-pont /api/v1/assignments I get the following error Question(s) not found: gps_af__Latitude, gps_af__Longitude . Here is the JSON object that I sending in the POST :

When I remove the variales gps_af__Latitude and gps_af__Longitude from the JSON, the assignmente is created without any problem.

Question : Is it not possible to pre-fill a GPS question when using the API ?

Thanks for your clarification

As per Design limitations by question type article the GPS question is preloadable. Note, the table is agnostic to the method of preloading via uploading a file or by submitting a corresponding API query.