You pull the handle. The handle moves ok. The valve does not open.
The cable has become detached from the valve.
This is what others have done. It is what I would do if I had that problem.
Estimate where the valve is if it is covered by bottom cover. Cut a three sided hole directly below the valve. Leave the side of the hole toward the front uncut. Use that side as a hinge and open the cover.
Evaluate the break and decide on corrective action. The valve is usually a 2 to 3 inch deep approximately rectangular plastic device. The cable may have unscrewed, broken, the cable attaching fitting may have broken, or other failure.
Go from there. Close the hinged cover. Tap the seam with high quality exterior grade tape.
I wish you good luck and happy trails ahead!