Hi @Ximena225
Custom Promotions have other requirements as well besides the 3 bookings. My guess is your new listing doesn't meet the 60day median price requirement:
Why Can't I Set Custom Promotions For Certain Dates
https://www.airbnb.com/help/article/2719
"When we calculate the discounts, we look at the 60-day median price for each date. In other words, we line up all of the prices you had set for that date from lowest to highest, and the price that falls in the middle is the median. If we don’t have a 60-day median price for a date, it won’t be eligible for a promotion. The date must be:
- Currently unblocked
- Unblocked for 28 of the last 60 days
- Less than 90 days away"