Download the Typewriter+ preset and drag the Typewriter+.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 "typewriter+". If not, open the dropdown menu and select "Refresh List."
With a text layer selected, apply the Typewriter+ preset.
By default, Typewriter+ will add 2 “Animation” keyframes. One set to 0% at the current time indicator and one set to 100% 2.5 seconds ahead.
You can edit these keyframes and add more to adjust the speed of the typewriting animation.
By default, Typewriter+ will animate in one character at a time. You can change this setting to animate the text based on words or lines.