The Unit Testing feature isn't that widely used in my experience. What I observe mainly is testing being done by developers on individual automations with varied pieces of data. Testing done by QA and above is generally focused on the output and whether or not it met the business requirement.

If you want more automated testing, then you could use the unit testing feature to run a series of automations (assuming they were disassociated with your UI). This would rely on your applications having constant data that you could prevent changes to, so that you can always get consistent results back.

In practice though, I generally observe testing of automations as a more manual process, especially if it is an RDA project (since this relies on user interaction and the state of the applications they are working with). For RPA testing, feeding the project with known data could be used to validate those results against the results expected.

You should reset your Toolbox and the unit testing tab will be available on your Toolbox.

I do not have any other suggestions other than what I shared in my reply earlier.