installer.php file question

Hello,

I need to reinstall a website which has an issue. The website I want to retore is down and we have no access to it from front end or backend. The problem is I need to take the backup zip file which our hosting provider made which is the latest backup version we have (and I cannot use the duplicator file which is 3 weeks old).

I would like to use the installer.php file to install the website, but the only installer file I have for this website is from 3 weeks ago. Do you have any generic installer.php file we can download?