The main tool we're using to stitch together Crowd and Nextcloud is the User and Group SQL Backends app. Start by installing it on your Nextcloud instance.
Make sure that Python and Pip are installed on your system. After that, execute pip install passlib.
Find a comfortable directory in your system (here we'll use /home/atlassian-password) and copy files getPasswordHash.py and checkPassword.py into it.
Find your Nextcloud installation directory (usually /var/www/nextcloud) and copy Atlassian.php into <nextcloud_installation>/apps/user_sql/lib/Crypto. Note that this action will have to be repeated every time that user_sql is updated. Make sure to replace /home/atlassian-password in the file with whichever path you had chosen on the previous step.
Finally, configure the User and Group SQL Backends app as follows, but with your own IP and password:
