Trying to create a Development Site but Template option not showing up when I create new site collec

Hi, 

Trying to create a Development Site but Template option not showing up when I create new site collection.

I am following Microsoft doc: 

https://docs.microsoft.com/en-gb/sharepoint/dev/sp-add-ins/create-a-developer-site-on-an-existing-office-365-subscription

However the "Template Selection" does not appear as a field to choose from (see what I have below):