Check your account information email that was sent to you when you opened SvoFX.
If you have lost the email and do not know it, please contact support so we can reissue a demo account password.
Note that you can trade without MT4 password if you use SVO application.
*Note
If you initially open a demo account with your cell phone number, demo account information will not be sent to you. Please contact support for your demo account password.