Yes, it's possible to display an external calendar using embed code on each Webflow collection page by storing the embed code in a collection field and using the Embed element. Here's how to do it properly.
Webflow doesn’t support storing actual HTML in rich text/plain text fields for rendering automatically — you must use this content inside an Embed element.
<div> or iframe code using Webflow's Add Field (+) to insert the CMS field dynamically.{{wf {"path":"calendar-embed-code","type":"PlainText"} }} inside the Embed element.
Use “Add Field” (lightning bolt icon) in the Embed window to dynamically insert the calendar code from the collection.
To display a unique external calendar on each CMS collection page, store the calendar embed code in a Plain Text or Rich Text field, and then insert that dynamically into an Embed element on the Collection Page template. Always test on the published site, as dynamic embeds don’t render in preview.