Cannot import any media into Davinci Resolve Studio 15

So I just bought Davinci Resolve Studio 15 on Mac App Store, the app installed perfectly but I couldn't import any files (I tried to import PNG, JPG, MOV, MP4), tried drag and drop and import directly from drop menu, nothing worked.

I am using iMac (Retina 5K, 27-inch, 2017)
4.2 GHz Intel Core i7,
32 GB 2400 MHz DDR4
Radeon Pro 580 8192 MB
High Sierra 10.13.6 (17G65).

Please help.

Thank you