To implement address autofill in your WhatsApp Flows after the ZIP code is entered, the correct approach is to use the data_exchange action, triggered by form submission or by screen navigation, rather than on_select_action (which is not available for TextEntry/textInput components).

How to Achieve Address Autofill:

1. Once the ZIP code (zipCode) field is entered, submit the form or navigate to the next screen. here

2. Configure the screen or form to use the WhatsApp Flows Data Endpoint (data_channel_uri). The form's data (including zipCode) is sent to your server via data_exchange action.

3. Your server responds with the corresponding address information (street, city, state, etc.) in the data payload.

4. On returning to the next screen (or updating the same screen via dynamic properties), populate the remaining address fields using init-values set to dynamic data references, such as ${data.street}, ${data.city}, etc.

Example Workflow

1. User enters ZIP code.

2. User taps "Next" or "Lookup Address".

3. Form data is sent to your endpoint (data_exchange).

4. Server responds with address data.

5. Next screen (or same screen updated) loads with pre-filled address fields.