The preferred method of using a Character Animator scene in an After Effects project is via Dynamic Link (i.e., drag a Character Animator scene from its Project panel in the the Project panel in After Effects, or import the .chproj file into After Effects and select the Character Animator scene to use).
If you still use the PNG Sequence and WAV export functionality from Character Animator, the older script to import it into After Effects is no longer bundled with the latest versions of After Effects CC. However, you can still import it in the following ways:
If you still have After Effects CC 2017 installed, from your current version of After Effects, choose File > Scripts > Run Script File, then navigate to the Scripts folder for After Effects CC 2017, and select the New Comp from Character Animator Recording.jsx script to run. If you don't have the older After Effects still installed, download the archive file containing the .jsx script file.
Import the exported scene manually using the same steps as in the script, i.e.,:
Choose File > Import > File, then select the first PNG file from the PNG sequence.
With the imported PNG footage selected, choose File > Interpret Footage > Main, then under Frame Rate, set "Conform to frame rate" or "Assume this frame rate" to the frame rate of the scene in Character Animator. Click OK.
Choose File > Import > File, then select the WAV file (if one exists).
Select both the PNG and WAV footage, choose File > New Comp from Selection, then make sure "Single Composition" is selected and "Sequence Layers" is not selected. Click OK.