Activate an inactive Booking.com promotion, so it is on sale again with its current discount, dates, rooms and rate plans. Read it with GET /channel_accounts/booking/promotions first to check what will go on sale. Returns changed: false when the promotion is already active.

• 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.
• 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.