As an administrator go to Admin Settings>Tracking & Data Organisation >Manage Tags and make your 'Interaction Tags' visible by using the kebab menu (3 dots) to the right of each Tag. This will create a star next to the tag.
Note: For auto tagging to work, each Tag must be starred (visible) and selected (green tick) under the 'Interaction' icon.
Interactions created with word/words matching the visible Tags exactly will trigger the auto generation. For manually adding additional Tags use the 'Generate Tags' button in the Annotations card or the Manage button in the Tags card.
