I could connect to MyCloud Home easily using the now discontinued app and have tried to follow the WD instructions to connect using Finder. I can connect as a Guest but that does not show me my files, so is no use. When I try to connect as a registered user then macOS throws me a login screen that I cannot get past.
I have no idea what username/password combination it is looking for (the one I use for the MyCloud website does not work here) and there is no functionality for forgotten credentials.
Perhaps you have not read the dozens of emails and notifications from WD in the last 9 months and the hundreds of posting on this subforum on this subject. The support article mentioned on the bottom of the post is the one you need, but here it is again:
This update introduces a new ‘local access feature’ to My Cloud Home, My Cloud Home Duo, and ibi products. This will enable users to use their device in a local network without connecting to the internet once local access is enabled using the dashboard. The Dashboard is a browser interface to enable local access. You can launch the dashboard from the web applications (https://home.mycloud.com/) and (https://ibi.sandisk.com/).
To learn more about local network access, please visit our support article.
Of course I have read all the emails and, as I said in my original post, tried to follow the instructions, so sending them again was rather silly. Those instructions say click on Manage Device but that does not work as I get a Not On Local Network error and those instructions do not mention that this can happen let alone explain what to do when it does.