The maximum number of supported neopixels is 60.
Only RGB versions are supported, so no RGBW neopixels. An external power supply should be used when more than 8 are being used.
Ensure that you have the pin correctly defined in your board.txt file. Here is an example.
led.neopixelPin = 1.24
For configuring them, use this documentation for reference.
Do not try to update the neopixels during motion or a momentary pause in movement would be caused.
It is ok to change their status at the start and end of a print.
Don’t be tempted to use daemon.g unless you are able to arrange it to take place at a layer change.
This may not work at all on any pin on the SKR-Pro as Neopixels really need a 5V control signal, which is why many boards like the GTR and SKR V1.4 have specific neopixel pins. Those pins have a level shifter that boosts the 3.3V signal to 5V. The SKR Pro does not have this. Sometimes you can make it work by providing the neopixels with a lower than 5V supply voltage, but it pretty much depends on the pixels that you have. Another option would be to use a level shifter.