Problem getting payment gateway strings in the correct language

I have my own developed payment gateway that loads the strings correctly on the thank you page (payment instructions).

On the email the client receives the payment instructions for this payment gateway are in english and not the current website language. All the other email strings (from ‘woocommerce’ textdomain) are correctly loaded in the current website language.
This is due to the fact the order is saved and the email sent in a ajax call on checkout and my plugin tries to load the admin locale and not the current website one.

How did you fixed this for the ‘woocommerce’ textdomain and how can I fix this for my plugin also?

https://wordpress.org/plugins/woocommerce-multilingual/