You can insert images directly in PM. Do as below:
Put Credit Memo in "Edit Mode"
Position the mouse pointer where you want to insert the image so that a "black frame with a plus sign" appears.
Select "Image" in the dropdown "Element type" and select your image file and click "Ok"
Alternatively, you can drag an image file to the segment / title you want. When you drag an image into a title / segment and the "black frame with a plus sign" appears, you release the image, ie "drag and drop". The image is inserted automatically
