The solution to your problem is to set the manager user and secret correctly in your fop2.cfg file. Check that manager_user and manager_secret have a valid user/password as configured in /etc/asterisk/manager.conf.

Here is the section in the online documentation that explains how to do that in detail:

http://www.fop2.com/docs/#ConfiguringtheServer

In order to test if you set that user/password correctly is to run, from the command line, this command:

/usr/local/fop2/fop2_server --test