I don’t want to re-download the entire vault of 3 GB to add that file and re-upload it again. And I want to upload the file to that vault, not to create another vault. Is there a solution?
You can access your vault directly online with cyberduck.
I said I deleted the vault.
I have found the solution. So even if you don’t have the original vault on your computer, you can still upload a file to that vault anyway.
So I went to my cloud storage, I downloaded the “masterkey.cryptomator” file, then you have to create a new folder in the same directory with the “masterkey.cryptomator” file named “d”. Next, go to Cryptomator and add a vault, select that “masterkey.cryptomator” file, unlock it, and add your new file that you want to encrypt and upload, then, lock the vault and upload your file.
I tested it, and it worked, I created a small vault just to test, I uploaded it to the cloud and deleted it from my computer, then I tried this solution, and when I downloaded the “test” vault again on my computer, I could see the old files and the new file together.