I see this question gets asked a lot and there is no real solution to it.
It has to be different for each product so obviously we need to use metafield but meta field won’t let us insert anything other than richtext? Please help.
You cannot actually connect to metafield if the type is different.
Metafield type of url cannot be connected to a richtext.
In order for you to use the dynamic source, the metafield type and schema type must be the same.
In the collapsible row schema, you need to add similar to these lines.
{
"type": "url"
"id: "pdf_link",
"label": "PDF Link"
}
Then you add it to the iteration section for the blocks.