NAT / Fortigate 60 E, Ports Management

Hello Dear Members please need to share your experience. i am novice Indeed I installed an open source application on my 2008 server, it works well in my LAN (with port 80), it connects via the internal fixed ip of the server 10.10.10.3:80. The server is connected to an internet network that has a public IP address (xx.xx.xx.xx) and which is also configured on a firewall. the Fortigate 60E Firewall can be accessed from the outside with the Public IP I would like to access the application and my server from outside via the internet. I want to know how to do NAT on Fortigate 60E and write the traffic / port to the internal address of the server,   Thank you for helping me please, I remain available