NOTICE: We highly recommend using the new connection method outlined HERE
Using Certificate Files: (legacy)
In your "Welcome email download the attached: yourusername.p12 and truststore-intermediate-CA.p12 files
Open ATAK app
Click the menu (☰) icon
Click on Settings
Click Network Tab
Click Network Connection Preferences
Click Manage Server Connections
Add a server to your device by pressing the three dots in the upper right-hand corner
Name: anything you want to identify the server you are connecting to.
Address: your servers IP or Domain name provided In the "Welcome to sat.vkintsys.com" email
Tick: Advanced Options
Streaming Protocol: SSL
Server Port: 8089
Un-Tick: Use Default SS/TLS Certificate
Tap: "Import Trust Store" then select the downloaded
truststore-intermediate-CA.p12The Password is: atakatak
Tap: "Import Client Certificate" then select the downloaded
yourusername.p12fileThe Password is: atakatak
Tap: OK (you should now be connected to the TAK server.
Need Help?
Contact EOTAK Support by clicking the support button 
in the bottom right of your screen.