I would like a sticky button on my mobile page

I would like a sticky button on my mobile page, but can’t manage to find out how.
I want it to look like this site on mobile: 5 Reasons Why 1,000s Of Coffee Drinkers Are Switching To Javy


Here is my public share link: https://preview.webflow.com/preview/probeer-clayandglow?utm_medium=preview_link&utm_source=designer&utm_content=probeer-clayandglow&preview=ab6ead2450a71af3a5b3c1138bb40368&pageId=624efb482dd6fd6d1d4efb57&workflow=preview