The organisation's owner switches ticketing on under Settings › service desk. Targets are minutes of business time within the hours you set, so the clocks pause overnight and at weekends.
Set the business hours and time zone, then the first-response and resolve targets per priority. Categories and canned replies are managed on the same tab. Press save settings.
Resolved tickets close themselves after the number of days you set; a requester reply before then reopens. BE AI triage and automatic knowledge writes are the two switches at the top.