No scribble option

An iPad Pro 10.5” with iPadOS14 does support the new Scribble feature.

First, check that iPadOS14 is installed:

Settings > General > About

If you haven’t already updated, do so now:

Settings > General > Software Update

Ensure that your Pencil is Paired with your iPad:

Connect Apple Pencil with your iPad - Apple Support

If you have successfully updated to iPadOS14 - and paired your Pencil with iPad - verify that Scribble is enabled in Settings:

Settings > Apple Pencil > Scribble - set to ON

If the your Settings do not show Apple Pencil or the Scribble option, a forced-restart of your iPad may be helpful. A forced-restart often resolves an isolated issue:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.