Moodle doesn't have a restore.php script. But you are in luck cause moosh does!
Restore done via moosh
https://moodle.org/plugins/view.php?id=522
https://moosh-online.com/
https://moosh-online.com/commands/
From last link above:
course-restore
Restore course from path/to/backup.mbz to category or existing course.
Example 1: Restore backup.mbz into category with id=1
moosh course-restore backup.mbz 1
Example 2: Restore backup.mbz into existing course with id=3
moosh course-restore -e backup.mbz 3
One line script looks like:
moosh -n course-restore /path/to/backupmbzfile/to/restore/restorethisone.mbz 20
The 20 on the end is a category. Category on your site should be hidden ... like a category called 'staging' and it's ID number is 20
Did this very thing for a gentleman who does things pretty much like you want to do them.
PM me and I'll give you his contact EMail address. Think he can vouch that it works and works without error/fuss/muss.
'SoS', Ken