Judging from the current situation in the figure, because the shift lever does not have the first half, it can't shift gears normally, and the second half of the shift lever may get stuck with the tripod rod due to deformation when shifting gears backwards. The temporary repair method can be as follows: firstly, unplug the rubber of the tripod, put a long iron pipe around the tripod and pull it forward, so that there is enough distance between them, so that it should be possible to shift gears backwards, and then ride to the repair shop to repair the fourth or third gear. Now it's the fourth gear, you can start it directly without correction, and then ride to the repair shop in the fourth gear.

Generally speaking, if the shift shaft is bent, it can be corrected. Remove the shift lever, put an iron pipe on the shift shaft and try to pull it forward gradually. Basically, you can straighten the shift shaft and then change the shift lever.