Because of some popular programming memes, I thought localhost is, well, only exist in your local machine. It's true, but on top of that, you can actually make it accessible to the internet, which means available to everyone, for some amount of time (not forever or anytime).
In order to do this, it's really simple, all you need to download ngrok . Here are the list of video tutorials from Twilio:
Only a few simple things you need to do.
And some articles about it:
https://www.freecodecamp.org/news/testing-webhooks-while-using-vagrant-for-development-98b5f3bedb1d/ ( don't worry about the virtual machine, you don't need one .)
Well, you might wonder, why would you ever need to expose your local host to anyone? For me, I was trying to use an online service to send a POST request to my localhost database. Obviously the online service doesn't like that, it requires an URL that can be accessed by online tools, not some http://localhost:4000 , so, ngrok helped create a valid URL that can be accessed to my localhost, and by any requests from the internet.
It's kinda like allowing the world to see a corner of your bathroom. With you offer it and nobody really ... cares.
Perhaps you will never need to use it, but, for me, without knowing ngrok, I might take forever to figure out how to access to my current company's database which are complicated. I figured it would be hard to try it on my local machine. However it was really easy, a few reading documentations and boom it is done with ngrok.