Installation WP: Stuck on step 5 in

I am stuck at the last step of installation
Hi there

With Filezilla, I moved the full wordpress installation folder to /subdomains/blog/httpdocs/

So you understand that I would like to install WP to a subdomain (blog)

To achieve the step 5 (Final script) What do I need to enter as url address? ‘https://blog.mysite.com/blog/wp-admin/install.php’ or ‘https://blog.mysite.com/wp-admin/install.php’ or ‘https://mysite.com/blog/wp-admin/install.php’ or ‘https://www.mysite.com/blog/wp-admin/install.php’?

I have got these error messages with the 2 first options: ‘Not Found The requested document was not found on this server’ or ‘Forbidden You do not have permission to access this document’

For the 2 other ones, I have got the usual page from my website: ‘page not found’

I am pretty sure it is a very little error but which one??? An idea anyone?

Many thanks