Unable to add items to Adonis Portfolio

I have been following the Theme Instructions for adding a portfolio to my website, but I cannot find how to actually add items to my portfolio categories. Via these instructions, I should see an option to "Select Type" (per #3 on the list of instructions). However, I do not see this option, only the option to "Enable On", then # of Items, followed by drop downs to indicate the portfolios, and lastly "Button Link" and "Button Text". Where should "Select Type" be?