If  the supplied earbuds are unsuitable they can be replaced but have to conform to these specifications

The audio output from the pen is Analog only. It will not work with digital earbuds or head sets. Any that have microphones are digital and will not work.

The best option is to use a passive USB C to 3.5 mm adapter and basic earbuds with no microphone.

This information applies to the USB adapter - Do a online search for USB-C Type C to 3.5mm Aux Audio Jack Passive Headphone Adapter and there will be options.

USB-C cables can also be categorized as passive or active. Passive cables do not have any active components, while active cables have built-in circuitry that can boost the signal and provide higher data transfer rates. It preserves the audio quality without using the extra power required by digital.