Add a new instagram widget

Follow the instructions here.

The Theme is Not Responsive

If the theme is not responsive on your phone/tablet, make sure you've disabled the Mobile view from the Theme page (first, make sure to set it to Default, then disable it).

If the Mobile view is not turned off, Blogger will force its own plain responsive view on some devices.

You can use to see how the theme you've purchased/want to purchase will look on different devices.