In a board view, click on an Item. The item panel will expand, click on the Add view button.
Find the app you want to embed and click on Add to item.
The embedder will be added to the item panel, displaying instructions on how to retrieve the URL of your document.
Now click on Settings, then Create New Column.
Add a Text column to the board.
Close the item panel. You can now rename the Text column to your liking (e.g. “Embed URL”).
Paste the URL in the corresponding cell under the new column.
Click on your item to open the item panel to see the embedded document.
Done!