Hi @EFYBangalore,
Welcome to the Community.
You can use Zapier to trigger a Zap in GetResponse based on a custom field value. Start by selecting GetResponse as the trigger App and choosing 'New Contact' as the event. During setup, specify the custom field and its desired value. When a new or updated contact matches that value, the Zap will trigger, allowing you to send conversion signals to LinkedIn, Google, or Meta. Just ensure the custom field already exists in GetResponse.
I hope this helps. If you have any other questions or if there's anything else I can assist you with, please feel free to ask.