premier customers should have the extended data manager available to them. This is a third oarty add-on only available to Premier customers for download. You may be able to add a second website field using the extended data manager. See documentation https://docs.storelocatorplus.com/blog/extended-data-manager/
The Extended data manager will appear under the General tab when activated.
Once you have added an extended data field element , it will appear available under your individual locations fields as you scroll down
To add the optional data field in the results layout, You will need to know some CSS/html to change the results layout.