How to politely urge others to pay back the money

The reasons for paying back the money should not be too specific and vague.

The simplest: "sorry, I'm a little short of money recently." Can you pay back the money I lent you last time? " "I am really in trouble. Do you think you can overcome it and think of other ways? " "I really need money these two days. Can you call me before tomorrow? " "There are some bad things at home, please, please think of other ways."