The API restrictions can be used to restrict the usage of the APIs to allow requests only from certain IP addresses.
It is possible to allow only certain IP addresses to call the DIBS API's.
This is done by going to Security > DebiTech DefenderTM > API Restrictions and clicking Activate.
Don't forget to add an IP address first.
To add an IP address write it in the text field and click Add.
Notice that when this feature is enabled only the listed IP addresses will be able to call the API's.