How to fix this function? (If able let me see the full source code)

Please help me to complete the online programmer Academy. I have spent 8 hours looking for the point of the problem but until now I did not find the problem sought as well as the solution.

HERES THE QUESTION :

Complete the code snippet in a simple program on the side to be able to run well.

TODO 1:
Complete the declaration of the getFirstAndLast function which becomes an extension of the String class with the return type of the Map<String, Char> which serves to get the first and last character of its receiver value.

TODO 2:
Add a function to print the values of the firstChar and lastChar variables on the console.

If it is run, the console displays the following text:

First Letter is K and N for second letter

You can get any character in a string by its index.

val charAtIndex4 = someString[4]

Indices always start at 0 so the first char will always be someString[0]. You can get the last char by using someString[someString.lenght - 1]. Also kotlin has extension functions to get the first/last element of any iterable/character sequence (including string).

val first = someString.first()
val last = someString.last()

How about the implementation about the code it’s written on that picture? I don’t know the exact location of where to place the code…