In the nick of time -> used to indicate that something was done just in time

✅We arrived in the airport in the nick of time just as our flight was being called

✅The paramedics arrived in the nick of time and saved the person's life

✅I took my roast beef out of the oven in the nick of time. A few minutes later, it would have been burnt

Jump through hoops -> used to indicate a difficult or challenging task

✅I had to jump through hoops to get all this is paperwork done on time. It was a really challenging time

✅The candidate had to jump through hoops to get the job, but it was worth it in the end

Throw in the towel -> used to indicate giving up or admitting defeat

✅I'm going to throw in the towel. I really can't work this out (can't solve a math problem)

It is not rocket science = it is not difficult

✅Cooking an omelette is not rocket science. You break a few eggs, whisk them with some ingredients and voila!