Hello Nick,
Unfortunately, if you do not know the password for an AxCrypt-encrypted file you cannot open it, even if you can sign in to the account. This is by design, it’s just this situation that AxCrypt is made for and it works like this even if you actually are the original owner of the file.
If you think you almost know the password, we have a simple software allowing you to try to find your password, and you can download the most recent version from https://account.axcrypt.net/Download/AxBruteForce.exe and read of how to use it at https://forum.axcrypt.net/axcrypt-brute-force/ . Please note that we cannot provide support beyond this.
Please check the FAQ at https://forum.axcrypt.net/support/faq/ for more information.