Instead, I am getting this and after this redirect to login-register page. Slack Conversation

I don't really have an answer for you. Standard behaviour for an audience-restricted SuitePromotion on a SuiteCommerce site is to say that a restricted promotion requires a user to log in. If this a standard/advanced promotion running on a Site Builder site then I have no idea if this is expected or not, or the best way to prevent it from happening.

This is standard/advanced promotion running on a Site Builder site, while this is running on our testing site, I am not able to figure out difference and do that on other site.