There isn’t any excess white exterior cable to slide along as it’s ripped as per the photo. And there isn’t any excess interior colour cable (underneath the exterior white cable) to push into the unit or space within the unit. The best thing to do is buy a new one.
We have a Lakeland heated airer which is really useful for drying baby clothes. However, the white exterior cable then covers the wiring that goes to the plug has split.
The different internal colour wires look ok.
The plug says “Fitted with 3A fuse”.
Also there is writing on the heated airer...