argument --no-proxy has no effect, I think.
Searching the sources I can't find where that argument is used. I believe the relevant code is in https://git.ligo.org/lscsoft/gwdatafind/blob/master/gwdatafind/ui.py#L58
if port not in (None, 80):
cert, key = find_credential()
context = ssl.create_default_context()
context.load_cert_chain(cert, key)
return HTTPSConnection(host=host, port=port, context=context)
return HTTPConnection(host=host, port=port)```