Write a function for download and processing satellite images Sentinel-3 and creating an index NDVI

def Sentinel3_processing(date_start, date_end, path, folder_name):
    """
    This function download and processing satellite images Sentinel-3 and creating an index NDVI
    
    Parameters:
    
    date_start: Start date of the search in format YYYY-MM-DD
    date_end: End date of the search in format YYYY-MM-DD
    path: Path where to save the downloaded data
    folder_name: Name of the folder which will be created for saving data
   """