I’m successfully interacting with my private Trello content in Obsidian, thanks to @Floran!
His plugin: Convert URL to preview (iframe) has a pop-up that allows me to navigate through the ‘Log in’ process, after which the content previews correctly.
Below is what I’m using for the embed code, but as a noob, I’d be happy for any improvements/suggestions.
Board view
<iframe src="{yoursharelink}" frameBorder="5" width="700" height="700">></iframe>
Single card view
<iframe src="{yoursharelink}" frameBorder="5" width="400" height="420"></iframe>
Search results view§
<iframe src="https://trello.com/search?q=board%3A%22{yourboardname-url-escaped-noquotemarks}{searchterm-noquotemarks}" frameBorder="5" width="420" height="800"></iframe>
Links:
* https://github.com/FHachez/obsidian-convert-url-to-iframe
§ https://webapps.stackexchange.com/a/118061/272845