Moodle user language

Hello,
When a user is created in our store and makes their purchase, the integration is happening normally, except that when being directed to Moodle, the interface is getting in English, even the default Moodle language being set for Brazilian Portuguese language).
Both our store and our Moodle have a language set to Brazilian Portuguese.
In the database, all users created from the store using the MooWoodle integration are set to “en”, and we would like to see them in “pt_br”.
We suspect of the plugin because when creating a user directly in Moodle, the same one with the interface in Portuguese as standard.
Is there a way to interfere with this in any part of the code?