Hello Pascal,
Please download and install the KSDK1.3 mainline to KDS,
then when you create project , you can see the KL03 chip.
Download it at here :
https://nxp.flexnetoperations.com/control/frse/product?entitlementId=123594587&lineNum=1&authContact...
About how to install the KSDK1.3 to KDS , you can refer to "Getting Started with Kinetis SDK (KSDK) v.1.3.pdf"
(under the KSDK1.3) -> Install Eclipse update . Or you can also refer to here New Kinetis Design Studio V3.0.0 available
Have a great day,
Alice Yang
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