Can you tell what's wrong

Question

https://code.sololearn.com/cc1WAXSvkRd8/?ref=app

Answer 1

This works:
https://code.sololearn.com/coOVUDO833Qa/?ref=app

Answer 2

to take the string and change replace the chars in it with random ones

Answer 3

Andre Daniel thank you very much (　^ω^)