setup apache reverse proxy from localhost to domain.com/etherpad - apache2

Question

Good evening,
I am trying to set up my apache2 reverse proxy
(following https://github.com/ether/etherpad-lite/wiki/How-to-put-Etherpad-Lite-behind-a-reverse-Proxy)
for etherpad lite
(following https://www.howtoforge.com/tutorial/ubuntu-etherpad-editor-server-installation/, except for the nginx part).
I use http->ssl redirection. Since I use letsencrypt I can only access domain.com and not etherpad.domain.com (at least firefox won't let me and I want to avoid changing that certificate each time I add a new site). So I would like to access my etherpad just as I do access my other sites: domain.com/etherpad. However I always get a 404 trying to get to the site. Looking at a working example, in my nextcloud.conf file I have a line saying:
Alias /nextcloud /local/path/to/nextcloud
However the etherpad reverse proxy virtual host file looks entirely different, the key difference is etherpad not having a local folder but only a mysql database. (Please correct me if this is wrong)
So I tried changing the ssl example from the second link to the following, but it does not work. Please understand that I changed domain name and some internal paths, but "apache2ctl configtest" succeeds and the service is running without error.
<IfModule mod_ssl.c>
<VirtualHost *:443>
ServerName randomisedDomain.com/etherpad
# SSL configuration
SSLEngine on
# If you hold wildcard certificates for your domain the next two lines are not necessary.
SSLCertificateFile "/working/path/to/fullchain.pem"
SSLCertificateKeyFile "/working/path/to/privkey.pem"
ProxyVia On
ProxyRequests Off
ProxyPreserveHost on
<Location />
AuthType Basic
AuthName "Welcome to the randomisedDomain.com Etherpad"
AuthUserFile /working/path/to/etherpad.passwd
#AuthGroupFile /path/to/svn.group
Require user etherpad
ProxyPass http://localhost:9001/ retry=0 timeout=30
ProxyPassReverse http://localhost:9001/
</Location>
<Location /socket.io>
# This is needed to handle the websocket transport through the proxy, since
# etherpad does not use a specific sub-folder, such as /ws/ to handle this kind of traffic.
# Taken from https://github.com/ether/etherpad-lite/issues/2318#issuecomment-63548542
# Thanks to beaugunderson for the semantics
RewriteEngine On
RewriteCond %{QUERY_STRING} transport=websocket [NC]
RewriteRule /(.*) ws://localhost:9001/socket.io/$1 [P,L]
ProxyPass http://localhost:9001/socket.io retry=0 timeout=30
ProxyPassReverse http://localhost:9001/socket.io
</Location>
<Proxy *>
Options FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all
</Proxy>
</VirtualHost>
Any help for rerouting the localhost domain to randomisedDomain.com/etherpad is greatly appreciated !
Best regards
MAPster