Hi @Mihaela60
This is a complex topic with lots of moving parts. Use caution when using the Airbnb custom promotions feature. It's a great tool, but you need to understand how it works before applying custom promotions. If you have lots of discounts set (weekly, early bird, last minute, etc.), when you apply a custom promotion to dates, your discounts can "stack" on top of one another and give the guest a steeper discount than you intended. I would start by reading through the help articles below and a thread I reposted below on the topic:
Why aren’t custom promotions available for my listing?
https://www.airbnb.com/help/article/2720
Why do my prices change when I create a custom promotion?
https://www.airbnb.com/help/article/2721
Create a custom promotion
https://www.airbnb.com/help/article/2982
Why can’t I set a promotion for certain dates
https://www.airbnb.com/help/article/2719
Do you really understand How Airbnb custom promotions work?
https://community.withairbnb.com/t5/Help-with-your-business/Do-you-really-understand-your-promotion-...