Help making a collapsible palette

I’m working with GoJS and AngularJS. I’d like to have my palette be collapsible, and here’s what I’ve tried, but it didn’t work.

<button data-toggle="collapse" data-target="#checkPalette">Check Steps</button>
<go-palette id="checkPalette" model="checkModel" style="width:200px; height:200px; background-color:lavender"></go-palette><!-- angular directive -->

I’m afraid I’m not familiar with Angular, but see:

For an example of a collapsible palette.