I decided to have a play with FOP2. The latest installation instructions have this:
### Manager Credentials
Before starting the FOP2 service, some basic configuration is required in *fop2.cfg* and probably in */etc/asterisk/manager.conf* (in many backends you can configure that in */etc/asterisk/manager_custom.conf* ), because the FOP2 daemon connects via TCP to the Asterisk Manager Interface (AMI) using a username and secret. The basic daemon config is covered [here](https://www.fop2.com/docs/installation.php#ConfigurationServer).
Once that the files are in place and the manager credentials configured you will have to start the service. There are a number of ways to do that. The best way is to use a proper init script for your distribution, another way is to start it from /etc/rc.local.
You can always check if the manager credentials are correctly configured, and also verify if your license is ok, by running the command:
```
/usr/local/fop2/fop2_server --test
```'
There is nothing there about how to configure these files.
I added a user from the GUI as you suggested. In the Permissions tab, I don’t see fop2 listed. When I try to login from mysite.com/fop2, I get “invalid credentials”
Normally fop2 puts its AMI user in /etc/asterisk/manager_custom.conf whereas the GUI puts them in /etc/asterisk/manager_additional.conf - I would check that you don’t have credentials in both places.