How to Back up iPhone to External Hard Drive on Mac/Windows

How are you to Back up iPhone to External Hard Drive on Mac/Windows?I need to Back up iPhone to my External Hard Drive on Mac computer,Whether have you more method to help me quickly to Back up iPhone to External Hard Drive on my Mac?If you have more method to solve this question,I will thank you very much,I'm looking forward to your answer.Best wish: Merry Christmas !