can’t upload images

I have just installed Envira Gallery, just basic version. I am looking at the main screen where you add images from the gallery, or external source. There is no link to click saying ‘select files from your computer’ (see screenshot https://www.dropbox.com/s/o4e00aiomozjg3e/Screen%20Shot%202017-03-10%20at%2014.20.13.png?dl=0). I tried dropping an image in the blank space, but it just previewed the image, no confirmation that the image had been imported into the gallery. I’m sure I’m missing something really obvious. Can anyone help?