Since v22.2 there are now Reports and Legacy Reports. As far as I am aware, there shouldn’t be anything to modify in any .config file to get the Reports functionality to work.
For Reports:
For OnPrem implementations, you need to run the ECM installer again and select the option on the last page to install reporting.
For cloud implementations, you need to click the button for the Epicor team to enable and install them within your environment.
For Legacy Reports:
For OnPrem implementations, you need to install them via the ECM Client, as @Anthony_Gercar as mentioned.
For cloud implementation, legacy reports are no longer available to the best of my knowledge, although perhaps they are also available via the ECM Client.