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Go to your Applications Folder > open Image Capture and see if you can scan in the image using Image Capture.

see > https://www.macworld.com/article/2867001/exploring-the-many-miracles-of-image-capture.html

and/or > https://soundsupport.biz/2015/10/18/how-to-scan-using-image-capture/

What iMac model do you have?

What system version are you running?

How do you have the printer connected to your Mac?

Have you tried the fixes in this Apple document: If you can't print from your Mac or iOS device - Apple Support.