eZee Software do not allow me to post payment on checked in room, from payment detail tab, the new button.Why is it so?

If the user does not have Privilege to “Add settlement in open date” then it’s possible that new button is disabled and the user would be not able to make the payment.

For assign this privilege loginto:

eZee configuration >> User >> Edit that particular user >> and tick mark “Add settlement in open date” and save, restart Front desk and check.