[Thumper]

I was confused with the term "clutch pedal". I thought you meant clutch lever (left hand side of handlebars). The lever in front of the left foot is a gear shift.

If the gear shift is free to move up or down, then with engine OFF, try gently rocking the bike forward, and back with some pressure on the shift lever(shouldn't take amuch pressure). It will shift when things line up inside the engine case.

If this works, I still think your clutch cable might just be too loose.

In your video, I see the detent getting pinned by the sprung piece. It seems to be in the right position. Try gently rolling the rear tire while trying to shift it. No clutch is needed for this when the engine is off. If the dogs in the gears on the countershaft/driveshaft are not lined up, it won't shift. Normally the wheel it turning and the engine is turning while shifting. Rolling the rear wheel will allow the dogs to align, so it can shift.