Fill in your link's info, pick a style, and get both the meta tags and the actual 1200×630 card image to host — so every share looks exactly how you designed it.
Workflow: download the PNG → upload to your server (e.g. public_html/og-card.png) → point "Image location" at it → paste tags into your header. Test in a fresh chat thread — iMessage/WhatsApp cache previews hard.