Install Grav without Shell Access

Hi everyone,
i try to install grav without any shell access.
i uploaded gravcore+admin to the webserver but now i only recive 404 error. i read that i have to generate a admin user, but how if i´m not able to access via shell?

Thanks
Kind Reagard
Matthias

Found this link that maybe of help.

https://learn.getgrav.org/16/troubleshooting/page-not-found