I have 3 websites and 3 of them have klaviyo accounts.I need to add  sending domain for these . for that i add root domain as xyz.com in the 3 and create sending domain separate for 3 of them . Like promotion.ab,promotion.cd ,promotion.de,is there any issue to add like this?The @ usually means that it is set in the root domain, and currently each country domain is set in the xyz.com domain zone. Can I register a txt record to xyz.com?
If I choose to create a separate domain zone for each country domain, then face the following issues The existing country domains are registered with “shops.myshopify.com” as CNAME records, and CNAME records cannot be registered with other records in the same domain name. Also, route53, which is currently managing the domain, does not allow you to register information other than AWS as a CNAME record in the root domain. Therefore, we need to change the country domain to A record and register it based on IP.

Any possible suggestion?