How do I create a Terraria server on my Android phone?

I have never created a mobile server, but you can try this:

Hosting via mobile device:

What you need:

1. You need to be on Wifi
2. Need a new and good device to host the server

What you have to do

1. Tap on multiplayer menu and choose the host option --> now you are hosting a multiplayer session
2. To play online you need to forward the port 7777. There are tons of guides in the internet how to forward ports
3. You MUST use the internal IP adress tied to your devicein the port forwarding process. You find the the internal IP here:
4. ANDROID: Go to “Settings” and tap on “Wi-Fi” settings”. Here tap and hold on your connected network and then select ”Manage network settings”. Now check the checkbox next to “Show advanced options” and select “Static” under “IP settings” You’ll find the device internal IP address under the “Gateway” section.
5. iOS: Go to “Settings” Tap on Wifi Tap the little i button with a circle around it located next to the wifi network to which you are connected. You’ll find the device internal IP address next to the second entry labeled "IP Address"
6. Find out your external IP. Can be found here https://www.whatsmyip.org/
7. Now everybody can enter your server with the external IP and the port 7777