Change some fields of a Booking.com promotion: discount, name, audience, minimum stay, non-refundable, stay dates and weekdays, additional dates, booking date and time windows, last-minute or early-booker window, rooms and rate plans. Only the fields you send change; everything else stays as it is on Booking.com, including the excluded dates (change them with POST /channel_accounts/booking/promotions/excluded_dates). rooms, parent_rates, additional_dates and stay_date.active_weekdays replace the whole list. book_date: null and book_time: null remove those limits; send a JSON body for that, since a form body cannot tell an empty value from null (400). The promotion type cannot be changed.

• Booking.com activates a promotion on every successful update, so an inactive promotion returns 409 unless you send activate: true.
• Some promotions, such as new_property_deal, cannot be changed (409). geo_rate promotions only accept discount, and mobile_rate promotions only accept discount, target_channel and parent_rates, because Booking.com does not return their other fields; other fields return 409.
• Sending the same request again is safe.
• Returns 501 while creating and editing promotions is not enabled for your account (it is enabled separately from POST /channel_accounts/booking/promotions/excluded_dates).
• Limited to 10 promotion writes per minute per Booking.com property, shared with POST /channel_accounts/booking/promotions/excluded_dates, in addition to the account rate limits; 429 responses include Retry-After.
• Values Booking.com rejects return 400 with the Booking.com code in error_msg (for example DISCOUNT_NOT_IN_RANGE, ROOMS_INVALID, TARGET_CHANNEL_NO_ACCESS).
• 502 means Booking.com was unavailable or the result could not be confirmed; the change may still be applied within the next few minutes.

Requires a writable access token.