Drop a HTML on the page.
Put: <style> #center { display: flex; align-items: center; height: auto; } </style> inside the HTML (or in header, if it is a paid app plan).
<style> #center { display: flex; align-items: center; height: auto; } </style>
Give the #center to the text element ID that you need to be vertically centered (without the #).
Done!