I have these types:

type AUnion = 'A'|'AA'|'AAA'
type BUnion = 'B'|'Number'

type ValueType = {
'A': string;
'AA': string;
'AAA': string;
} | {
'B': string;
'Number': number;
}

I have a function receiveing two params, one is the value and another is the message:

const myFn = (value: ValueType, message: AUnion | BUnion) {
  const mappingResult = value[message]
  return mappingResult 
}

When I do this mapping, the TS shows error that ‘A’ does not exist on type ValueType, how should I correct this type?