You can always use some JavaScript within a Nanonflow.
This code will toggle the toggle-btn for you. I'm assuming you only have one .toggle-btn on the page.
// Select all elements with the class .toggle-btn
var toggleBtns = document.querySelectorAll('.toggle-btn');
// Iterate through the NodeList and simulate a click on each element
toggleBtns.forEach(function(toggleBtn) {
toggleBtn.click();
});
Good luck!
Yes that is possible, see the documentation on this subject here: https://docs.mendix.com/refguide7/sidebar-toggle-button/