How to load sentinel 1 data into the Snap?

hello every body , i am new user in snap, i downloaded level 0 sar data from alaska university data source but when i tried to open it into the sanp i encountered this error message " no appropriate product reader found"

ho i can solve this problem??
thanks to all

you cannot process RAW products with SNAP (or most of other remote sensing software). I would recommend using GRD for standard analyses.

Please also see here: Radiometric & Geometric Correction Workflow

i want to make interferrogram by pair of s1 images, how i can find free s1 slc files?