Use STM32 ST-LINK Utility, cannot find the target, STM32L4R9ZIY6PTR-WLCSP144. Four ST-LINK pins connected: SWCLK, SWDIO, Vtarget, GND. Note:NRST pin of STM32L4R9ZIY6PTR is not connected.

[Tesla DeLorean]

Does the ST-LINK Utility support L4+ devices? Use STM32 Cube Programmer.

If the ST-LINK can't find the part and connect, its probably not viable.

[HYuan.1]

Only when connect NRST pin to ST-LINK, the STM32L4R9 can be connected. But from the data sheet the NRST pin is not needed.