I've tried these, but they return an 'Invalid URL' error.
requests.delete(URL+'/api/v3/requests/'+ID+'/notifications/'+convoID, headers={"authtoken":KEY}, verify=False)
requests.delete(URL+'/api/v3/requests/'+ID+'/notifications/'+convoID+'/move_to_trash', headers={"authtoken":KEY}, verify=False)
requests.delete(URL+'/api/v3/requests/'+ID+'/notifications/'+convoID, data={'input_data': json.dumps({'type':'conversation'})}, headers={"authtoken":KEY}, verify=False)
requests.delete(URL+'/api/v3/requests/'+ID+'/notifications/'+convoID+'/move_to_trash', data={'input_data': json.dumps({'type':'conversation'})}, headers={"authtoken":KEY}, verify=False)