If it is stock Chinese, ie Chinese menus, then the (unspecified) NVR will likely give a 'Language mismatch' error on attempting to add.
If it's running 'hacked to English' firmware, it will likely add OK. But it will not be updateable.
As seller answered its stock Chinese, ie Chinese menus its a model: DS-2CD2345-I, they were previously used, price is around 15 euros, maybe it can be lowered to 12 euros. They originally paid them 125 euros.