How to implement a very fast (automated) sending of previously recorded POST requests?

Question

Software testing

Colleagues, please give me advice in an area with which I am very superficially familiar:
You need to help a friend test an online store for its behavior with a noticeable number of simultaneous purchases .
What should be done:

• Log in as a buyer in Chrome, spy on the POST request that goes at the last stage of the purchase, record it and then send a series of such recorded requests to the server.
  You can run the entire series from one user, the main thing is that he is authorized on the site.
  

The main gag is that you need to send it quickly - 7-10 requests per second (i.e. automation is needed).
I'm not going to DDoS anyone, sending within 3 seconds will be enough.
I started to figure out how to do it. Of the tools embedded in Chrome, I found Postman and Insomnia . Also found Selenium .
And here it stuck. The tools seem to be really powerful and right away I can’t even figure out the possibilities and understand if they can do what I need.

1. Can you please tell me if I have chosen the right tools?
   
2. Is it worth further studying them and, if so, which one and in what direction (I would prefer the simplest option)?
   
3. If the options above don't work, what should you use instead?
   

Answer 1

You can easily implement this scenario in JMeter.

Answer 2

cURL

Answer 3

If curl is complicated, you can try siege , by the way, it can also emulate a rather serious load. Certainly. captcha must be disabled.