unable to view DVR CPD560 remotely

[mobio.dev]

Hi expert,

I setup dvr CPD560, connect to router DSL-2640T and able view using static ip,
then to view remotely, i create ddns acc with dyndns.com,
then in dvr settings, I enable ddns and enter username & password as i create ddns acc, host name into domain, and choose the ddns server, and click on apply
but when login again its shows login failed,

but when i entered the host name which I created with dyndns.org, its enter into gateway

is there is any extra setting to do

thanks in advance