Shift +Tab doesn't work

I frequently use the Tab key to create outlines. Often, I need to back tab in order to maintain the outline format. I'm used to using Shift+Tab from my Windows experience, however when I try that on my new MacPro, it doesn't work. It just continues to tab to the right when what I need to do is tab to the left. Is there a different shortcut on the Macs to perform this function? I'm running Ventura 13.0.1.