Adding Cisco 7841phone to Asterisk

I need some help adding a Cisco 7841 3pcc phone to FreePBX. I added the server ip in the proxy space on the phone settings but it doesn’t connect. I do not see it trying to connect in the Arterisk CLI. I am able to get a SPA8800 to connect to use as a gateway but the Cisco 7841 phones will not connect.