URL Meta offers a free API to extract images, descriptions, and other metadata from a URL to be displayed as a preview. We switched to using URL Meta after a tool called Page.REST, also used for extracting metadata, was discontinued. The free plan has a 10,000 monthly quota.
Head to https://urlmeta.org/ to create a free account and find information regarding the API. Once you create an account and click to log in via the email sent to you, you can access your API Key (you might need to refresh to see it on the page). See the image below for an example of setting up URL Meta in the Bubble API Connector plugin. Make sure to combine the word "Basic", a space, and a base64 encoded value of "email:key" for the "Authorization" value, where "email" refers to the email you used to create a URL Meta account and "key" is the API key for the account. You can use a website such as https://www.base64encode.org/ for base64 encoding.
The image below shows an example of an API call response, which can vary depending on the URL used.