Contao 3.22 - installation issue - 404 error: file not found

[Gévard]

Hello,

I use Webfection for my website hosting.
I create a website with the URL contao.mywebsite.com
When I try to install via contao.mywebsite.com/contao/install.php
I first got a page with the GNU license, and when I accept the URL become: http://contao.mysite.com/contao.mysi...ao/install.php and I got an error 404:
"The requested URL /contao.mysite.com/contao/install.php was not found on this server."

What I missed?
Thanks for helping

[KlausGrenoble]

Happy new year !
This can help you probably:
http://contao.klausgraf.fr/metamodel...doubleurl.html