How can I automatically tag customers by language in Klaviyo?

[coco44]

Hello,

I have my website in French and English (Canadian website).

I want to use Klaviyo and want to create 2 lists automatically for the emails: one in French and one in English.

How can I tag automatically my customers based on their language?

When I filter au Shopify it works example here:

But when I click on the customers I have no tags.

So how to tag them automatically based on the language? It will solve all my problems.

Thanks,

C.