Uniassist uploading documents for VPD with ALEVELS

I'm trying toapply via uniassist rn, but idk if when uploading the documents, do I put all the scans of the certificates in 1 pdf file ( 8 Olevels+ 3 Alevels), or each subject submitted alone?

If anyone knows pls tell me and if anyone has applied using A Levels, do you have any tips? or idea how they calculate the VPD , so I got AAB what would my result maybe be?