Sadly you will have to play the GHTV mode in Guitar Hero Live as much as possible right now because the feature will be gone forever this December. The servers for the feature will no longer function meaning you cannot play most of the DLC songs that the game has to offer.
The Activision Support page made the following announcement: “We want to thank you for being valued fans and let you know that as of December 1, 2018, the GHTV mode within Guitar Hero Live will no longer be available to play. On that date, we will terminate the service for GHTV and servers will be shut down. Console versions of the GH Live mode will continue to operate as usual.
As of June 1, 2018, iOS versions of the Guitar Hero Live game for mobile will no longer be available for download via the app store. However, if you currently own the app and have it installed on your device, you can continue to play the GH Live mode on your installed device. Please note: if you update your iOS software, the app may no longer be supported.
Additionally, on June 1, 2018, all GHTV in-game purchases will be turned off. Players can continue to use their Hero Cash and items on hand until the GHTV sunset date of December 1, 2018. Thank you for playing GHTV, and head to GH Live mode on console to continue to play.”
Guitar Hero Live came out in 2015 for console platforms, but the game was unable to revive the music genre for a new generation. You can still play the games on the disc as only GHTV is going away forever.