Source: https://storage.googleapis.com/play_public/supported_devices.csv
Redmi,Redmi 9,lancelot,M2004J19C
Redmi,Redmi 9,lancelot,M2004J19G
Redmi,Redmi 9 Power,lime,M2010J19SI
Redmi,Redmi 9 Prime,lancelot,M2004J19C
Redmi,Redmi 9 Prime,lancelot,M2004J19I
If your Redmi 9 Power has the device codename lime you cannot flash the ROM for lancelot.
If you have the device you can confirm device codename with