Having problems backing up photoshop elements 19 catalogue

Hi

1. Tried to perform an incremental backup to external hard drive after doing the first full back up but when I check incremental backup the save file tab is greyed out so I'm having to perform a full backup each time....any ideas??

Ensure that you have selected the backup path options fields in the dialog, after which the Save option enables. Refer to this help guide for steps:Back up or restore catalogs in Elements Organizer 15 and earlier versions

2. Also I'd like to back up to a DVD or Blu Ray disc but these options don't appear as an option when I go through the backup wizard. I've got an apple external CD drive and a pioneer bdr xd05.

Backing up catalog to CD/DVD is not supported in Organizer. You can use other external drives like pen drive, network drives, hard disk etc. to save back up to them.

Thanks.