To answer my own question, I found this document:
https://docs.openvpn.net/how-to-tutorialsguides/virtual-platforms/amazon-ec2-appliance-ami-quick-start-guide/
public_hostname -- hostname that clients should use to contact the server.
admin_user (default=openvpn) -- Access Server administrative account name.
admin_pw -- administrative account initial password. Note that
this parameter is communicated to the instance via a
cleartext channel. A more secure method would be to ssh
to the instance and use the passwd command to set the
password.
license -- Access Server license key (without a license key, the
Access Server will support up to 2 concurrent connections).
reroute_gw (boolean, default=0) -- if 1, clients will route internet
traffic through the VPN.
reroute_dns (boolean, default=0) -- if 1, clients will route DNS
queries through the VPN.