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-,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.