Setup external interrupt on Arduino R4 WIFI by setting bits

Official Hardware UNO Family UNO R4 WiFi
1

On the Arduino Uno R3 it is easy to setup an external interrupt by setting appropriate bits in the appropriate registers, for example like this:

void setup(){
    EIMSK |= (1 << INT0);  //Enable interrupt on pin 2
    EICRA |= ( (1 << ISC01) | (1 << ISC00)) ; // Set trigger event to rising edge
}

void loop(){
}

ISR(INT0_vect){
     //Do something
}

Is it possible to setup an external interrupt on the Arduino Uno R4 without using the 'attachInterrupt()' function, i.e. by setting bits just like on the R3? If so, I'm very interested in seeing the code for setting up the interrupt and how to write the interrupt service routine itself. Also, I don't want to use the interrupt request manager class or any other native functions to setup the interrupt.

3

Hi Delta_G and thanks for your answer.

Is there no example code of anyone actually doing this? I feel I have scoured the internet and I have also come across your other post, but I still haven't been able to setup an external (or any kind of interrupt) without using the built-in native functions and classes.

The reason I want to do this is for educational purposes. I dislike the idea of the necessity of having to use a library or a specific function that does 20 things of which I understand none in order to learn something.
For the Arduino Uno R3 Nick Gammon's webpage was a huge help, but nothing for the Uno R4 seems to exist yet, unfortunately.