Login to Drupal via https

login.sh

#!/bin/bash
# Obviously change name and pass values and example.com domain
curl --insecure \
  --cookie ./cookie.txt \
  --cookie-jar ./cookie.txt \
  -e example.com \
  -d "name=admin" \
  -d "pass=admin" \
  -d "form_id=user_login" \
  https://example.com/user

Then you can do authenticate requests like for instance download file from private directory:
$ curl --insecure --cookie cookie.txt -O https://example.com/admin/config/system/backup_migrate/settings/destination/downloadfile/manual/Example.com-2025-12-02T06-29-37.mysql.gz