MEGA provides up to 50 GB of free, fully-encrypted cloud storage

They also provide a number of CLI tools that allow you to connect and manage your cloud storage from the command-line. Install from https://mega.nz/cmd

rclone would be my preference, just because of familiarity and the abstraction that it provides - but it does not allow the use of the 2FA/MFA configured on my MEGA account

In my case, I wanted to backup my photos to the Cloud but I needed to exclude the *.RW2 (raw) files for space.

mega-login --auth-code=999999 <email> <password>
mega-exclude -a *.RW2 *.nef
mega-mkdir /images
mega-sync /data/images /images

Using the mega-sync command without any parameters allows you to see the current status

$ mega-sync
ID LOCALPATH                                                                         REMOTEPATH                                                                        ActState   SyncState     SIZE  FILES   DIRS
 0 /data/images                                                                      /images                                                                           Active     Syncing   28.22 GB   9555    270

You can use mega-find to ensure that no .RW2 files have slipped through (the mega-exclude patterns are case sensitive)

$ mega-find /images --use-pcre --pattern='(?i).*rw2' -l

I forgot to exclude .nef files from a different camera

$ mega-find /images --use-pcre --pattern='(?i).*nef' | while read file; do mega-rm -vvv "${file}"; done