Click New on the Connection menu.

Select Firebird.

Connection name: enter a connection name.
Server name: enter the Server name of the Firebird database Server.
Database name: enter the name of the database.
User: enter the user name.
Password: enter the database password.
SQL dialect: define which Firebird dialect to use. That should be consistent with the Firebird version of your database.
Enable Offline mode: Learn more here
Select User Groups who can view the Connection: Assign user groups with privileges to open objects from this connection.
Click Ok to establish the connection.
Important!
In order to fully exploit all MS Excel© export functionality it is recommended that you install the Firebird /InterBase (r) ODBC driver 2.0.
Please download and install form here:
http://www.dbxtra.com/Download/Drivers/Firebird odbc 2.0.0 win32.exe
Related
Connect to FoxPro - Database Container