I can't donwload complete genome of Culex pipiens pallens of the ncbi by API (Entrez): HTTP Error 400: Bad Request

Question

I am trying to download the genbank if possible of the complete genome of Culex pipiens pallens from the ncbi but I get this error. The URL of de ncbi. In the db variable that I sent in the fetch I already tried with nucleotide, genome, Gen etc. I thought that with assembly I would download it but no.

When I run the download_genbank() function, I get the error: HTTP Error 400: Bad Request

This is the page: ncbi culex pipiens pallens complete genome:

from pathlib import Path
from Bio               import Entrez
from Bio.Entrez.Parser import DictionaryElement, ListElement
from Bio import SeqIO
from Bio.SeqRecord import SeqRecord
from typing  import Union

def write_text(txt: str, filename: str):

Path(filename).parent.mkdir(parents=True, exist_ok=True)
Path(filename).write_text(txt)

def request_fetch(  db:str,
                id: Union[str, list[str], set[str]],
                file_format: str,
                filename: str                       ):
""" This function writes plain text in the type you specify.
    Typical types: 'fasta', 'gb', etc. 
    Should be used to download only a few files."""

if Path(filename).exists(): return

with Entrez.efetch( db=db,
                    id=id,
                    rettype=file_format,
                    retmode="text"      ) as response:

    content: str = response.read()

write_text(content, filename)


#GCF_016801865.1

def downloand_genbank(): 
request_fetch(      db="assembly",
                    id='GCF_016801865.1',
                    file_format='gb',
                    filename='cache/culex_pipens_pallens.gb') 

download_genbank()