Hello @Jasper_lin ,
To download SDK, goto https://mcuxpresso.nxp.com/en/welcome, choose the option "Select Development Board".

Then, search for your board model in the search box, build MCUXpresso SDK.

Choose two of the following depending on your situation. Download it.

Open your MCUXpresso IDE, drag and drop your SDK file into the IDE, and you can import SDK examples.

Hope it helps!
Best Regard
Liu