This is perfect tool for simple benchmark tests on your web server. It could be used to send a number of concurent HTTP requests so you can verify the app can handle the load or your rate limit config works as expected.
sudo apt install apache2-utils
Create 10 concurent sessions and send 100 HTTP POST requests to your API to test /login URL.
ab -c 10 -n 2000 -p ab.txt -T "application/json" https://api/login #ab.txt file { "username": "foo", "password": "bar" }