If you signed up before Aug 9, 2021, please click Previous plans to view your applicable plans.
Under the reports tab, when you click on Filter beneath the concerned report, you would only see the dropdown and dependent dropdown fields. Fields such as Single line texts, Check-boxes, etc. are not included.
For a data dump of all the fields, please navigate to the Tickets tab -> and do an export (highlighted in blue) from the right side of the tickets list view.