The last row in tunisian crochet is always a bind off row. While TSS is often used for binding off, any tunisian crochet stitch can be used. There are two commonly used types of bind offs. The pattern will include instructions explaining which to use.

Slipped Stitch Bind Off

Work the stitch as normal but instead of adding a loop to the hook, slip the new loop through the loop already on the hook. The video shows a bind off using Tss

Single Crochet Bind Off

Work the stitch listed as normal (two loops on the hook) then YO and pull through both loops on hook. This creates a stretchier edge than the slipped stitch bind off. The video shows a bind off using Tss