Before you proceed, you need Spaces installed on your phone.
How to add a new Tab?
Step 1 - Open the Space in which you want to add a new tab and Click on the three-lined menu icon located on the top right corner of the screen.
Step 2 - SelectAdd tab.
Step 3 - Select any template based on your requirement by clicking on plus icon beside the tab list and you will automatically be re-directed to the tab.