Atmega328p fuses for internal clock, need external crystal?

The ATmega328p are running at the internal 1 MHz oscillator by default, so you don't need an external crystal to set fuses and burn the bootloader.

I suggest you check out MiniCore, which makes it really easy to get started using the internal oscillator. I've also mapped the two pins you save by using the internal oscillator. That means you actually gain two more IO pins (that the Arduino UNO option doesn't give you). There's plenty of information in the README file if you're interested :slight_smile: