You can purchase and download the game and its official DLC directly from the Nintendo eShop .
This pack adds 4 skill-type Image Pulses of Azure Striker Gunvolt's "Merak," 4 skill-type Image Pulses of Azure Striker Gunvolt 2' 蒼き雷霆（アームドブルー）ガンヴォルト Azure Striker Gunvolt 3 Switch NSP/XCI [DLC/Upd...
The text you provided appears to be a typical title for a download page for for the Nintendo Switch, specifically for obtaining the game's ROM files (NSP or XCI formats) along with its DLC and updates. You can purchase and download the game and
Azure Striker Gunvolt 3 has received significant post-launch support: Product - Azure Striker Gunvolt 3 Official web site Azure Striker Gunvolt 3 Switch NSP/XCI [DLC/Upd...
A free demo is available on the eShop that includes the opening stage and the first mission, with progress carrying over to the full version.