Use a third party integration service capable of receiving a webhook and updating Airtable records. When the service receives the webhook, have it update the Airtable record. In Airtable, create a formula field that combines the webhook url with information identifying the record. Send this url to your users.
Pros
Users do not need to log in.
Can be more much more affordable than third party portal systems
Cons
There is no “confirmation” stage. Accidental clicks can update record data prematurely with no undo.
Airtable record history will not state who updated the record.
The link for the webhook can contain obsolete data.
Will typically open a browser window when the link is clicked, although you can adjust the styling of what shows in the browser window.
User cannot customize updates at all–the specific data changes must be hardcoded into either the formula field for creating the url or hardcoded into the third party integration system.