Download the Num preset and drag the Num.ffx file to:
Documents → Adobe → After Effects 2023* → User Presets
* or your current version
Inside After Effects, navigate to the Effects & Presets window. You should be able to find the preset by searching "num". If not, open the dropdown menu and select "Refresh List."
Within a composition, create a text layer. You can give it placeholder text* (i.e. “123”) and adjust the styling however you like.
*The placeholder text can be used to control the custom symbols (see Step 3).
With the text layer selected, double click the Num preset to apply it.
With the text still selected, navigate to the Effect Controls. Under the Num effect, you can customize the number formatting.
Make sure your expressions engine is set to JavaScript (File > Project Settings > Expressions).
With Num Pro you unlock additional controls under the Num Pro Effect.
Big Numbers
Monospace
When using monospacing, set the paragraph alignment of your text layer to center – you will be able to change the visible alignment under the Text Alignment control.