This filter alleviates the problem which arises when atto_ubicast tries to inject an <iframe> HTML tag directly into text fields. This works for teachers and "trusted users" but not all users and not in all locations. Optionally, the atto_ubicast cans insert an <img> HTML tag instead. This tag's usage is unrestricted and is then turned into an iframe at the rendering stage by this plugin.
You can either use the official files available in moodle.org or install the filter manually.
The moodle.org link is:
https://moodle.org/plugins/filter_ubicast
To install the filter manually:
cd moodle/filter
git clone https://github.com/UbiCastTeam/moodle-filter_ubicast ubicastFirst, you need to turn on the filter in the /admin/filters.php page of your Moodle instance.
Then, you need to enable the <img> tag insertion in the atto_ubicast plugin. This can be done in the atto_ubicast plugin settings: /admin/settings.php?section=atto_ubicast_settings.