Hi there,
Thankfully, this will be much easier in GP 3.0.
For now, your sticky navigation is only a button, so there’s no way to insert another button into it.
Perhaps the Mobile Header feature is worth looking into? Then you could do this:
1. Create a Hook Element:
2. Add your button to the element:
<a class="hide-on-desktop hide-on-tablet button" href="URL HERE">My button</a>
3. Choose the generate_inside_mobile_header
hook.
4. Set your Display Rules.
Let us know ๐