Retrieve GetYourGuide activities for a destination and handle booking

Steps

1. Authenticate to the GetYourGuide Partner API using HMAC-signed requests with your partner access ID and secret as documented in their partner portal.
2. Search for tours at a destination by querying the tours/search endpoint with cnt_language, q (destination or keyword), and date filters for availability.
3. Fetch the full tour details by ID to obtain pricing tiers, duration, meeting point, inclusions, and category tags.
4. Check availability for a specific date and participant count using the tour availability endpoint; the response includes option IDs (time slots) with their prices and remaining capacity.
5. Book by calling the booking creation endpoint with tour ID, option ID, date, participant details, and payment reference; store the GetYourGuide booking reference and retrieve the voucher URL.
6. Handle cancellations through the cancellation endpoint using the booking reference, respecting the refundable_until timestamp in the booking response.