The Airtable base structure is being refreshed automatically in the following instances:
Opening extension setting page.
Opening a form and a portal
In case the following does not work, you can force a refresh by:
Clicking the Sync button next to the "Base structure last refreshed" text towards the top of the configuration page.
Or, clicking the refresh button located at the bottom of the Airtable view, field, and table pickers. See example below.
