Prepare the server

Create the dedicated web root, FTP account and database.

Create a dedicated domain or subdomain such as desk.example.com. Do not use a URL subfolder.
Point its document root to an empty dedicated directory.
Create an FTP/FTPS account that opens directly in that document root; the wizard uses /.
Create an empty MySQL database/user with complete rights to that database.
Enable HTTPS, PHP 8.3+ and the required extensions.
Allow PHP to write storage and bootstrap/cache.