Ad said VPN was available, but now VPN is not available for my phone?

Just rejoined Norton/Lifelock.  Ad said VPN was available.  Trying to put NORTON on android phone.  Said it was NOT available for my phone.  Can someone  explain this please?  Thanks!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------

[Edit: Clarified title]

What Android version is on your device? 

Are you trying to install 360 Android that includes the VPN feature, or the stand alone Norton Secure VPN app? Both apps require a minimum of Android 6.