Long tests may be aborted at any time. Select the Abort Tests icon from the menu bar.
This looks like the old versionInstructions say there should be an abort button -
https://www.seagate.com/au/en/support/kb/how-to-use-seatools-for-windows-202435en/
Long Generic Test scans the entire drive for defects. It will take a long time to complete. Because this test reads every sector on the drive, the amount of time required will depend on the speed and capacity of the disk drive. The highest capacity drives often take 3 to 5 hours per terabyte to complete. At any time, feel free to Cancel the test without harming the drive. Long Test is completely data safe.