Yes, you can learn freestyle online if you have access to a pool to practice. You will need to send video of your swimming each week to the instructor. You’ll want to practice for at least two one-hour periods between class sessions. One two-hour session works, as well. If you can swim more, all the better!
Our last student to take this course (he took it privately) is now swimming on a masters team in Denver.
The online course covers every point and drill of the in-person course. It’s a very good way to learn.