This is not an answer to your question as it stands, rather a recommended solution for your underlying problem.

[VueScan][1] provides macOS support for nearly all scanners.  Your particular scanner is included in the list.  Connect your scanner to your iMac, install VueScan and run it.

You can download and run VueScan for free - but every scan will be watermarked.  So once you have discovered that it works for your scanner, you will need to pay for VueScan.  Though you may feel it is expensive, VueScan is cheaper than competitors like SilverFast. I bought the one-time professional edition many years ago and have never had to pay for upgrades. The standard edition is all you need.



  [1]: https://www.hamrick.com