Choose a data source
Use a public HTTPS endpoint that allows cross-origin reads and returns the JSON your component expects. Keep private credentials out of slide configuration. Give the slide a useful starting view for when the endpoint is unavailable.
Test the interaction
Activate the feed in a presentation and compare the value it shows with the source. For a hosted web app, open the embedded experience and try the main control. The host must allow its page to be framed.
Rehearse the fallback
Try the presentation on the network and device you will use. Check the saved picture for offline handouts and show the live link when the audience needs to use the controls.
Example brief
What if the feed becomes unavailable?
Include the unit, provide a useful starting value or empty state, and distinguish previously loaded data from a fresh observation. Rehearse with the feed unavailable so the audience still understands what the slide represents.