You can insert this to adobe_coeff.c file:
{ “Nikon Z 9”, { 13389,-6049,-1441,-4544,12757,1969,229,498,7390 } },
and this to cameras.xml:
<Camera make="NIKON CORPORATION" model="NIKON Z 9" mode="14bit-compressed">
<ID make="Nikon" model="Z 9">Nikon Z 9</ID>
<CFA width="2" height="2">
<Color x="0" y="0">RED</Color>
<Color x="1" y="0">GREEN</Color>
<Color x="0" y="1">GREEN</Color>
<Color x="1" y="1">BLUE</Color>
</CFA>
<Crop x="0" y="0" width="0" height="0"/>
<Sensor black="1008" white="15892"/>
</Camera>
<Camera make="NIKON CORPORATION" model="NIKON Z 9" mode="14bit-uncompressed">
<ID make="Nikon" model="Z 9">Nikon Z 9</ID>
<CFA width="2" height="2">
<Color x="0" y="0">RED</Color>
<Color x="1" y="0">GREEN</Color>
<Color x="0" y="1">GREEN</Color>
<Color x="1" y="1">BLUE</Color>
</CFA>
<Crop x="0" y="0" width="0" height="0"/>
<Sensor black="1008" white="15892"/>
<Hints>
<Hint name="msb_override" value=""/>
</Hints>
</Camera>
"
Enjoy