An index signature parameter type cannot be a union type

[Identity-labs]

What happened?

@citizen/client type is not usable without adding "skipLibCheck": true

This error happen at compilation :

node_modules/@citizenfx/client/index.d.ts:136:10 - error TS1337: An index signature parameter type cannot be a union type. Consider using a mapped object type instead.

136         [exportKey: string | number]: Function

which type should be declared here ?

Expected result

No error

Reproduction steps

include @citizen/client type in node/typescript project

Importancy

There's a workaround

Area(s)

ScRT: JS

Specific version(s)

FiveM/RedM

Additional information

No response