Booking Form Custom field for Referral Source

Add a custom field to the booking form which supports a drop-down list users can choose from to select how they found us:

- Ai Search (ChatGPT, perplexity, etc)
- Bing
- Google Search
- Google Maps
- Google Ads
- Meta (Facebook / Insta)
- Passing by
- Recommendation
- Tiktok


This is specifically for the Booking form, not a “Custom Form”.