Use hreflang tags in your theme

When search engines crawl websites, they look for hreflang tags to determine the language and region that the website is intended for, and then use that to serve the correct URL based on a user's language and location.

For example, if a store has a default URL of your-store.myshopify.com, and a Spanish language version of es.your-store.myshopify.com, then including hreflang tags in your theme will ensure that a customer located in Spain, or with a Spanish language setting, will be served the Spanish URL.