When you upgrade your Splinterlands account by purchasing the $10 Summoner's Spellbook, a HIVE blockchain account is created for you. This blockchain account is what enables you to own and transfer Splinterlands assets, but it also allows you to transact in many different ways on the HIVE blockchain, which branches out further than the Splinterlands game alone (see also Hive Dapps).
you already have hive with same your game name.
https://docs.splinterlands.com/hiveblockchain/accounts-and-keys