I have forgotten which theme version the automatic update code is added in.
Please login to WordPress dashboard.
On your WordPress admin menu, Please look for Appearance -> Theme Updates
You should see input to enter username and password.
If you are not seeing this input, this means that your theme version has not yet include the automatic update codes. You will have to manually download from your account to update.
If you have the inputs, Please check that your username and password is correct.
They are the same username and password to this forum.