If your Mac has a built-in SD card reader, that'd be the best/easiest to use to transfer photos.
If you don't have a card reader, try first using Apple's "Image Capture" application to see if it can recognize your camera and import photos.
You can always purchase a card reader (they are quite inexpensive). If doing so, go with a reputable brand and ensure the cable that the card reader would connect with, would work with one of your computer's ports (e.g. newer USB-C, or older USB-A/B).
Totally agree with Rick.
Macs seem to have particular challenges with Canon software - the software works fine of Windows, for example. So, the best thing to do is keep your processes as simple as possible, which means taking the camera out of the download pipeline. An SD card reader, either built-in or via a port, would seem to be the way to go.
If you just want to download images Ricky's recommended use of Image Capture is right on.
If you want EOSU for its other features then check the security settings in Privacy & Security. You may need to authorize folder and/or full disk access.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
04/20/2023: New firmware version 1.4.1 is available for EOS R3
03/30/2023: New firmware updates are available.
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM