I use strikethrough all the time to manage tasks on my projects. It's usually very simple to do it in other note taking apps, but in Notebook, here's what I have to do.

Right click on selected text, choose Font, choose Styles, select struck through from list, click apply.

Is there a shortcut for this anywhere? It's a little maddening to slow my flow just to cross something off my list.

I've attached a gif of me going through the whole process.