Hi filipvds,
By giving some extensions the possibility to access the wallboard that means that you have follow the next steps to configure each extension and log in:
1. logged in the management console
2. select an extension from the 'Extensions' list and double click to edit it
3. Select the 'Options' tab in the extension properties
4. check the 'Allows 3CX Wallboard Access' Option
5. The password used to log into wallboard will be the 'Access Password for 3CX Web Services' please note it down
6. log in to yourip.5000/wallboard using the extension number as user name and the 'Access Password for 3CX Web Services' as password.
Please verify that you have performed the above steps and you still have no access to the wallboard and if this has not solved your issue please let us know
Best Regards