asset store download blank

i want to download package (snaps prototype) from asset store i’m using unity 5.6.71f latest but download button can’t work

some tutorial show to instal probulder into packege manager i don’t have package manager in window menu or reset to default package in help, also manifest.jason i don’t have that file in my project
please help

152421-capturew.png

because of vision window bit 32 have unity 5 only that package more vision