To create a deobfuscation map for IL2CppInterop you need the unobfuscated version, and the obfuscated version of a game. you also need Cpp2IL.
.\Cpp2IL.exe --game-path "<path to obfuscated game root>" --exe-name <name of the game exe> --output-root ".\il2cpp_out_obf" --skip-analysis --skip-metadata-txts --disable-registration-prompts
for the obfuscated, newer version and
.\Cpp2IL.exe --game-path "<path to normal game root>" --exe-name <name of the game exe> --output-root ".\il2cpp_out_deobf" --skip-analysis --skip-metadata-txts --disable-registration-prompts
for the unobfuscated, old version.
then you can generate the mapping Il2CppInterop, the command looks as follows.
.\Il2CppInterop.CLI.exe deobf generate --old-assemblies="<path to cpp2il>\il2cpp_out_deobf\" --new-assemblies="<path to cpp2il>\il2cpp_out_obf\" --output=".\map" --include="Assembly-CSharp"
that's it. just rename your maps to the games version and youre done.