To subscribe or unsubscribe to folders in the Roundcube interface, perform the following steps:
Step 1: In the top right corner of the Roundcube interface, click Settings.
Step 2: Select Folders in the left menu. A list of available folders will appear.
Step 3: Select or deselect the check boxes that correspond to the folders that you wish to view or hide in the Roundcube interface.
Step 4: Click Mail in the top right corner to return to the Inbox. The left menu will refresh, and all of the selected folders will appear.