I totally forgot that i had a post here untill i screwed up my server by accident with no good backups and i had to do this all over again. (i had 2fa working before)

I started from scratch

For basic understanding
/app/data/extensions folder contains syslink files (shortcut) to read-only directories in -> /app/code/extensions/

The latter is where i wantto upload the totp jar file, but we cant because the filesystem is read-only.

#cd into /app/data/extensions

#download tarball
wget http://apache.mirror.digionline.de/guacamole/1.0.0/binary/guacamole-auth-totp-1.0.0.tar.gz

#extract the tarball
tar xvzf guacamole-auth-totp-1.0.0.tar.gz

here i lost it, i deleted the excessive folder containing files
and i am left with

/app/data/guacamole.properties

#/app/data/extensions/guacamole-auth-totp-1.0.0.jar

rebooted and nothing happened after login. I am positive that im logging in with admin account since there is no other. How could i forget to get this working?

I want to install the totp extension for guacamole using the guide linked below.

guide TOTP

So i went to the cloudtron terminal and figured that the
/etc/guacamole/extensions/ folder is actually the app/code/extensions/ folder.

The filesystem is write-only and therefore I am unable to move the totp .jar file there.

I am new to unix-based systems and afraid to break anything. I read about unmounting the filesystem and mount it with read-write permissions. After installing the extension I would unmount it again and mount it with read-only configured.

Is this the right way to do it ?
If not please provide me with advice on how to properly install the extension for cloudtron guacamole.

Thank you all in advance and my apologies if this is a repeated question in the forum.