Isolated margin trading allows you to limit your risks to a certain pair. You will have a separate account for this pair and only tokens from this pair can be transferred over there.
This feature is running in a beta period until January 20. Please keep in mind that margin trading is risky. Please do your own research and training on this topic. Further information can be found in the app help center.
If you are not registered on KuCoin yet, you can use TestingCatalog link to do so.