Documentation lack for Installation routine

[petrk94]

I tried to install the SolidInvoice with the distribution package SolidInvoice-2.2.3.zip
But after unzipping and reading the installing page, https://docs.solidinvoice.co/en/latest/guide/getting_started/downloading.html#installing-distribution-package-1

it didnt helped me to run the application, so I took a look on the Sympfony Application Deployment guide
https://symfony.com/doc/current/deployment.html

This is my htaccess:

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^css(.*)$ public/css/$1 [L]
RewriteRule ^images(.*)$ public/images/$1 [L]
RewriteRule ^js(.*)$ public/js/$1 [L]
RewriteRule ^uploads(.*)$ public/uploads/$1 [L]
RewriteRule ^bundles(.*)$ public/bundles/$1 [L]
RewriteRule ^static(.*)$ public/static/$1 [L]
RewriteRule ^swf(.*)$ public/swf/$1 [L]
RewriteRule ^(.*)$ public/index.php [QSA,L]

The application folder is in www.xyz.de/invoice

but all I get, when opening this address, I get the following application error screen:
Oops! An Error Occurred
The server returned a "404 Not Found".
Something is broken. Please let us know what you were doing when this error occurred. We will fix it as soon as possible. Sorry for any inconvenience caused.

What Im doing wrong? Im not familiar with symphony, can not just be added a simple install.php file to run all through?

My hoster is a shared hoster, called Uberspace, no root access, but access to SSH for my Shared host account.

Would very appreciate if you can help

Thank you