You can tag for many actions or inactions of your webinar
You can use the zapier app to registrant data, tag for seeing offers and clicking or not clicking, you can also do tagging for a webinar and apply tags like Registered, Came to webinar, Watched full, Did not come, Left early, Watched Replay, Asked a question..
First you choose the trigger and choose 1 of the 3 options in image below
If you choose to use tagging for webinar so you can apply a tag. These tags are applied after the event is over.
You must already have your tags ready in your CRM so that you can map them out within Zapier.