The blank form is now called the form view. It creates a new row in a table from a link opened in any browser. To edit an existing row, use the Extern form column instead. Both features can be shared with external people.
Pick the tool based on what the external person needs to do:
Tip. A creation form link can open with fields already filled in: prefill a form through the URL.
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Form view: create records with a form
Create new rows with a shareable form.
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Extern form
Let an external person edit an existing row.
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Customise the form with the visual editor
Layout, header, end message and sharing.