The new promotion technology is an awe-inspiring feature not available in Google Shopping.
While not testing this yet, it is recommended that you have your promotions on a dedicated page with all details in plain text. Also, avoid using images. Most likely, Microsoft can not extract promotion details from an image. We are mentioning this because many websites present promotions with an image instead of plain text.
Microsoft says they will crawl your website every 12 hours to find store-wide promotions. Promotions only applicable to a subset of products will not be used. Only promotions that apply to all products are valid.
To view your promotions go to Microsoft Ads > Merchant Center > Promotions
You can also opt-out of automated promotions by going to Automatic updates tab under Settings and selecting Block crawled data.
However, I have not found this setting in the accounts I have access to.