When you first install AI Tagger in your Zendesk account, you receive 100 free credits.

When you enable AI Tagger, it will start tagging tickets in the background, as they come in. Each ticket tagged costs one credit.

When you run out of credits, AI Tagger will stop tagging tickets.

You can check how many credits you have left, and top up your credits by clicking "Add credits", in the admin section.