They are not really necessary. They are used to tighten the string (between the footrest and the rudder) so that there is enough tension on the toe piece so that it pulls it forwards. See the attached video showing how to use it.
If the wheels on your kayak trolley become flat quickly, please check and rotate the valve clockwise tightly. If this doesn't fix the problem, there might be a slow leak. You can check it by spraying some soapy water and if it starts bubbling ...
1. Start by placing the seat on your paddleboard in the right position. 2. You will see two sets of straps. 3. Two are meant to be attached on the back, two on the front. 4. Attach the back straps to the board. 5. Arrange the seat again and attach ...