Css broken / page not found multisite WordPress

Dear all,

Since two days, I am fighting to get my Multisite live.
I have – as explained here https://www.totalcomputersusa.com/2012/11/moving-wordpress-multisite-to-a-new-domainserver/ :
– Uploaded the wordpress folder to www/
– Copied the DB on the msql host and modified the option / blogs / site / site meta / option (of the subfolder) with the domain name.

As a result, I have a main site working : https://click2revenue.alwaysdata.net/.
Though if I then click into dashboard, the wp admin panel is accessible but without css.
And If I try to change a setting, I get an internal server error.

If I then go into one of the subfolder https://click2revenue.alwaysdata.net/ukfragrance, then I have a not page found error. And the styles are missing.
Please note, that some of the element of the original site are still being displayed. Pictures for example.
I tried to activate a twenty 13 theme just to check, I got the internal server error too.

I know this is a recurring problem. And I red some other threads, I tried many of the possible solutions, but nothing really worked.

My wp-config :

/* Multisite */
define('WP_ALLOW_MULTISITE', true );
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', true);
define('DOMAIN_CURRENT_SITE', 'click2revenue.alwaysdata.net');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

htaccess

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase click2revenue.alwaysdata.net/
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) home/click2revenue/www/$1 [L]
RewriteRule ^(.*\.php)$ home/click2revenue/www/$1 [L]
RewriteRule . index.php [L]

</IfModule>

# END WordPress

I thank you all in advance for the help !