Key error in string format

Question

What is the error and means by key error here
https://code.sololearn.com/chod800biGvb/?ref=app

Answer 1

delete '=' from string like f'{param}' not f'{param=}'... because it tells you 'param=' is not a parameter

Answer 2

Why old way does not working?Царь СОБАКА - Догго I

Answer 3

Thanks giora now it works but without f string formatting code.