Once the script has loaded, it exposes a small API on window.Sendshot:
window.Sendshot?.open(); // open the feedback widget
window.Sendshot?.close(); // close it
Hook open() up to a "Send feedback" link in your menu or help panel:
<button type="button" onclick="window.Sendshot?.open()">Send feedback</button>
If you only want your own button, turn off the floating button under Customize → Behavior. The keyboard shortcut keeps working unless you turn it off too.
Using optional chaining (?.) means nothing breaks if the widget hasn't loaded yet or is blocked by an ad blocker.