Add Lynkist Website Chat to a Shopify store by pasting one line in theme.liquid.

In Lynkist, open your widget's Install tab and click Copy snippet.
In Shopify admin, go to Online Store → Themes. Next to your live theme, click … and then Edit code.
Open layout/theme.liquid. Paste the snippet just before </body> and click Save.
Open your store. The chat button shows on every page.

In Security → Allowed websites, add your shop's own domain and your your-store.myshopify.com domain if customers can reach it. When you change themes, paste the snippet into the new theme too.

Install on Shopify