Where to add If (_OSI ("Darwin")) {} line on SSDT-PLUG.dsl

I am clueless when it comes to SSDTs.. Any help would be much appreciated.. Where do I add the line for If (_OSI("Darwin"))? Is it even needed in this SSDT? I need to "Adjust [my] SSDTs with If (_OSI ("Darwin")) {}" so that these patches are only applied when I boot to the MacOS drive, and not my windows drive. (this is according to OpenCore Vanilla guide)

DefinitionBlock ("", "SSDT", 2, "ACDT", "CpuPlug", 0x00003000) { External (_PR_.CPU0, ProcessorObj) Scope (\_PR.CPU0) { Method (DTGP, 5, NotSerialized) { If ((Arg0 == ToUUID ("a0b5b7c6-1318-441c-b0c9-fe695eaf949b"))) { If ((Arg1 == One)) { If ((Arg2 == Zero)) { Arg4 = Buffer (One) { 0x03 // . } Return (One) } If ((Arg2 == One)) { Return (One) } } } Arg4 = Buffer (One) { 0x00 // . } Return (Zero) } Method (_DSM, 4, NotSerialized) // _DSM: Device-Specific Method { Local0 = Package (0x02) { "plugin-type", One } DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0)) Return (Local0) } } }