A formatted string is just like a regular string but has an f in front of the first quotation mark. This tells Python to interpret anything inside its curly brackets as a Python expression rather than as literal text.
There are many ways of formatting Python strings, f-strings are the latest but probably also the easiest to use:
e.g. Without using string formatting, a cruder approach would be:
str(minutes) + ":" + str(seconds)
but then also still need to figure the leading zero issue with the last part.
That doesn’t give us anything to go on - to give useful suggestions, we really need a specific description of the problem, or any error message that occurs.