by the way
US /baɪ ðə weɪ/
UK /baɪ ðə weɪ/

1.
au fait, à propos
used to introduce a topic or information that is not directly related to the current conversation but is considered relevant or interesting
:
•
By the way, did you hear about Sarah's new job?
Au fait, as-tu entendu parler du nouveau travail de Sarah ?
•
I need to go to the store. By the way, do you need anything?
Je dois aller au magasin. Au fait, as-tu besoin de quelque chose ?