Hey, I applied to Abertay Computer Arts in late 2019 and they didn't do interviews, they just did digital portfolio reviews. I can't speak to whether that's changed since but that was my experience. I did have in-person interviews for most of my other universities in early 2020 (pre-covid), but Abertay were specifically not doing them. Again, I don't know whether this has changed, but they may have told you via email about what to expect from the process, so check what info you've received from them.
My offer was based entirely off my predicted grades, personal statement and digital portfolio submission.
My digital portfolio was the most important aspect of my Abertay application.
My general portfolio advice is a combination of examples of iteration/development/design work (often the kind of thing you might do in A level), some drawings from life (e.g. still life, figure drawing, technical drawing) and imaginative work (work that demonstrates combining ideas imaginatively). Some places might request a variety of mediums, and this is often course-dependent - in this case you would want evidence of working in a 3D space, ideally digitally but any spacial work i.e. model making, textiles or prop-making, papercraft, pottery etc all show your ability to work in 3D space. Less is more, they want to see your ability to curate your work. Try and cover all of these areas thoroughly within the limitations they have set in their portfolio guidance. My Computer Arts application had just 10 pieces.
I received through UCAS that I had been given a conditional offer dependent on achieving the minimum grades (BCC) following their review of my digital portfolio. I don't remember off the top of my head how long this took, a couple weeks? I ultimately went to a different university that did interview me.