I have tried this once before and I cannot believe I am too stupid to figure it out.  Some years ago, I installed V11 and installed some free apps so I could get used to the environment.  Didn't like them.  Learning curve is very steep, but I wanted to try some free apps from the apps store but could not get them to appear on the list.

Now, I have tried again and the default accounting app is no longer an option so I tried downloading the Odoo Mates accounting module.  I followed all the instructions:

To install this module, you need to:

Download the module and add it to your Odoo addons folder. Afterward, log on to
your Odoo server and go to the Apps menu. Trigger the debug mode and update the
list by clicking on the "Update Apps List" link. Now install the module by
clicking on the install button.

Noting happens and I cannot find any troubleshooting help.  Lots of pages going over the steps to add the apps, but nothing about what to do when something goes wrong!