There is no place for a fuse in the battery pack connector that you attached a photo of. The fuse is in the scooter's original battery pack which is no longer installed on the scooter.
The best place for the fuse is between the positive battery pack wire or positive battery pack set of wires in this case, and the battery pack connector.
ATO and MAXI fuses are the most common type of fuses used for electric scooters and bikes. ATO fuses are available up to 50 Amps in our store, however, are more commonly available abroad up to 30 Amps. MAXI fuses are available up to 120 Amps. We carry both of these fuse types on our Fuses Page and we carry fuse holders for them on or Fuse Holders page.