Page 3 of the manual here
https://www.telescope.com/assets/pro...9513_06-15.pdf
Figure B shows the drawtube lock knob (The bigger one) and the tension screw (The machine screw half hidden by the lock knob) The lock knob needs to be fully released and the tension screw just tight enough to ensure that the drawtube does not slip when focusing inward and the scope pointed straight up.