How to open the xxx.fit file?

Hi.
I am new in zwift. I download my activity from zwift to my computer, the filename was xxx. fit.
How do I open it? Which program do I need to use?
I have Garmin connect.
Can I use my Garmin connect to opent the fit. file? How to do?
Best regards
Tri

Hi! Have a read of this post and see if you have more questions:

on garmin console choose upload browse on Zwift drag that file into your garmin and upload done!