Currently, there is not out-of-the-box feature available in UiPath to generate HTML or excel reports after test set execution.
I have built an UiPath library to generate test execution report once the test set execution is completed. We can also easily extend this to perform additional actions such as notifying user via email.
The library component along with the source code is available in the below Git repository
An example test automation project using this library along with a sample html report is available here
Sample HTML report screenshots