How can I detect which request type was used(GET, POST, PUT or DELETE) in php?

I think you should use use the variable $_SERVER['REQUEST_METHOD']

$_SERVER variable will let you know that which type of request you are getting. e.g

By using $_SERVER['REQUEST_METHOD']

For further details please see the documentation of $_SERVER variable .

$_SERVER['REQUEST_METHOD']

using $_SERVER['REQUEST_METHOD'] you can detect which type of request