Is this what you need?

val MorseCode = mapOf(
    "-.-.--" to "!",
    ".-..-." to "\"",
    "...-..-" to "$",
    ".-..." to "&",
    ".----." to "\'",
    "-.--." to "(",
    "-.--.-" to ")",
    ".-.-." to "+",
    "--..--" to ",",
    "-....-" to "-",
    ".-.-.-" to ".",
    "-..-." to "/",
    "-----" to "0",
    ".----" to "1",
    "..---" to "2",
    "...--" to "3",
    "....-" to "4",
    "....." to "5",
    "-...." to "6",
    "--..." to "7",
    "---.." to "8",
    "----." to "9",
    "---..." to ":",
    "-.-.-." to ";",
    "-...-" to "=",
    "..--.." to "?",
    ".--.-." to "@",
    ".-" to "A",
    "-..." to "B",
    "-.-." to "C",
    "-.." to "D",
    "." to "E",
    "..-." to "F",
    "--." to "G",
    "...." to "H",
    ".." to "I",
    ".---" to "J",
    "-.-" to "K",
    ".-.." to "L",
    "--" to "M",
    "-." to "N",
    "---" to "O",
    ".--." to "P",
    "--.-" to "Q",
    ".-." to "R",
    "..." to "S",
    "-" to "T",
    "..-" to "U",
    "...-" to "V",
    ".--" to "W",
    "-..-" to "X",
    "-.--" to "Y",
    "--.." to "Z",
    "..--.-" to "_",
    "...---..." to "SOS"
)

Then try printing MorseCode here and build your own in your IDE with that.

Kotlin: MorseCode[".--"] ?: "" or MorseCode.getOrDefault(".--", "")

Change that ".--" with a var that contains a single morse code.