Hello Olivier,
1. You must make sure your PEMicro Multilink Universal reversion can support the LPC product.
You can check it with P&E micro.
2. About the document for the debug config
You can refer to the MCUXpresso_IDE_User_Guide.PDF in folder C:\nxp\MCUXpressoIDE_10.0.0_344
page 20 chapter 3.7 P&E Debug Operation and Page 60.
3. You can click debug button like the following picture, it will search automatically.

Then choose the multilink and OK, it will enter in the debug mode.
Wish it helps you!
Have a great day,
Kerry
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