A contact button does not need a plugin, a script or an account. It is a link with some styling.
The idea
A phone button is a link that starts with tel:. A WhatsApp button points to wa.me followed by your number. A Zalo button points to zalo.me followed by your number. Give the link its own inline styles and no theme can break it.
Where the code goes
- For one page or post: a Custom HTML block.
- For every page: your theme's footer code area, or a Custom HTML block in a footer widget area.
Make it in a minute
Use our free button maker for a single button, or the site-wide contact buttons tool for a floating set in the corner. Both give you one snippet to paste.