power - what the best way to calculate Rg gate driver for Mosfet

I need to drive a MOSFET IPW90R120C3 from Infineon here the Specification of MOSFET

VDS @ TJ=25°C 900 V
Rdson @ TJ=25°C   : 0.12ohm
Qg = 270nC

Specification of driver IR2110

Isource: 2A 
Isink : 2A
VOUT 10 - 20V

ton/off (typ.) 120 & 94 ns
Driver supply : 15V

The switch frequency Fsw= 50KH

what the best way to calculate the resistance Rg to drive proprely the MOSFET ? best regards

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