Where do I find the Epson Scan software 64 bit update

I had the same problem. The app was an older 32 bit app. Initially Epson did not have a 64 bit driver/app, but they do now. However, It may not work with some older scanners (like mine). If that is so, you may purchase VueScan. it works with most scanners and has a lot more features than the Epson app. If they have a free trial, I would try it out first since with the latest Catalina update, my scanner no longer worked with VueScan. The last option would be to use Apple's Image Capture app in a scanner mode. It will work as long as you have the needed Epson driver, although you will not have all the features a full featured app offers. Hope this helps.

I have an Epson WF-3520. I've downloaded all of the available drivers from Epson to address the 10.15 OS update. Printer works fine, however, I can't get the scanner to work. Epson is not providing Epson Scan 2 for this printer. Does anyone have a workaround?

You would have to get that from Epson, assuming there is such a thing.

Try using the Apple program Image Capture to execute scans, see if that works.

Frank...

https://www.hamrick.com/vuescan/epson_wf_3520.html

They are as noted here.