Assuming you have assigned the plugin on a track and monitoring is active; create a new bank library preset on the track using the track menu. Right click on the new preset in the preset list (or press Alt+Enter with key focus in the list) to get to the properties dialog for the preset. Choose the ‘Import…’ button and locate the fxb file.
After exiting the dialog the new bank should now be loaded into the plugin. You may additionally want to use the track menu ‘Update programs list’ to update the list of presets in the ‘Programs’ folder to the new contents of the plugin preset bank.