Geolocation Redirect Popup SEO

Question

What is the correct SEO way of redirecting customers to other websites based on their IP? We currently have 2 websites, one is for brazil and one is for other Latin America. The 2 websites are different aside from language, hosted both on Shopify but not the same account, the brazil website only shows a few products and has a different design.  

My method of redirecting is using GeoIP API, then show pop up asking them that there is a brazil website available and asking them if they want to proceed or stay. 

Just want to ask what should we do for its SEO and if it will have a negative impact on our websites. Do we need to declare ref lang and country?

Answer 1

From Google's point of view, redirecting users based on IP is a bad practice for SEO:

Avoid automatic redirection based on the user's perceived language. These redirections could prevent users (and search engines) from viewing all the versions of your site.

and further in the same guideline:

Do not use IP analysis to adapt your content. IP location analysis is difficult and generally not reliable. Furthermore, Google may not be able to crawl variations of your site properly. Most, but not all, Google crawls originate from the US, and we do not attempt to vary the location to detect site variations. Use one of the explicit methods shown here (hreflang, alternate URLs, and explicit links).