In Shopify, it's important to ensure that all your languages are correctly assigned to their respective domains and markets. Failure to do so will prompt an error message within your langify’s language section. It is easy to fix, follow the steps below for a quick resolution:

• Look for the error message in your langify languages section. 
• Click on the highlighted "Here" to access your "Languages and domains" section in Shopify.
• Click on “Add languages” in the top right and assign your language(s) accordingly.

Here a quick Video:

Note: You can also go there in Shopify directly:
Settings > Markets > Languages and Domains > assign language to domain/market Here their guide