Increase precision of flexible polyline in HERE Maps routing HTTP request

I am using a HERE maps HTTP request in the following format:

https://router.hereapi.com/v8/routes?origin=42.55009,-83.11662&destination=42.55277,-83.11675&transportMode=car&return=polyline&apikey=[api-key]

This returns a polyline encoding "BG00hlxCrkhx-E0oBzB82C3DgoBpC". I am able to decode the coordinates using the Python API. However, the default precision is only 5 decimal places (~meters resolution) in the decoded list.

Documentation of flexible-polyline mentions possible higher precisions (~microns) defined by the header-content. I would like atleast 6-7 decimal places of resolution for the returned polyline. How can I configure this through the HTTP request?