https://example.com?email={{responder_email}}
. utm_source
attached to the url, and you want to capture that data, you can use an external variable. The URL that redirects to Formsort should look something like https://flow.formsort.com/client/{{your_account_name}}/flow/{{your_flow_name}}/variant/{{your_flow_variant_name}}/?utm_source=example