[GraphHopper] Create a route with only an start point

[Laura Barroso]

Hello:
Searching for start point to settle this:
I want that a user introduce the amount of meters and the start point, so
that I can create a route that meets that criteria...of course I will have
to create a final point and I will propose a route for him.
This is where Im stuck, I being looking on the GHResponse, GHRequest...
but graphhopper is suppose to have always the start and the end point.
Is there any way to achieve this????
Sheers
Laura.