Encrypting files

Hi, I am looking for an option to encrypt some files, more specific my backup files which I want to upload to Dropbox.
My Nextcloud is running on Ubuntu Server 18.04, which has no GUI.
I tried to install Cryptomator, but was not able to run it.

Does anyone know another application? Or can anyone help me installing and running Cryptomator?

Best regards,

You may have a look at restic and rclone.
restic is a backup program. And rclone can write to Dropbox.
Use the forums search function to find a post with anexample script.

Thanks for replying.
Writing to Dropbox is not a problem, first problem is encrypting.
I’ll have a look at restic and rclone.

Best regards,

restic will do encrypted backup.