Search gasstations along the route in flutter

I want to show gasstations along my route(from origin to destination on the selected path) using google places api.I have tried with google places api-https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=-33.8670522,151.1957362&radius=1500&type=gasstations&key=API_KEY. But this only gives gasstations within the radius of particular location.I want to get gasstations on my route. Please help me to achieve this in flutter.