If you want to reset the VNC password, you can do it directly through the customer area. You can refer to the following link for how to login to your VNC.
After successfully logging into the customer area, then in the Options section select + VNC Password.
Then there is a column that requires you to fill in a new VNC password. In this section, write down your VNC password correctly. Upper and lower case letters and symbols are very sensitive.
If so, reboot your VPS, because changing the VNC password requires rebooting the server so that the configuration can be applied immediately.