- PNG Sequence export isn't default in AfterEffect
- Let's take AE CC as an example (Cuz Lab has it)
- If you are doing for the first time:
- Double click to open the desired to export sequence first:
- Select Composition→ Add to Render Queue, (or CTRL+M/CMD+M on your keyboard)
- Click on Output Module's arrow and select Make Template... (Assuming you are exporting more than one)
- On the popup window, Enter the name "PNG Sequence" and click edit
- On another popup window, Select Format "PNG Sequence" and Channels "RGB+Alpha" (Important as you don't want your characters to have a square background)
- Click OK to confirm both
- Select where to export to
- Click Render
- Double click to open the desired to export sequence first: