According to Inspirit Online's official Facebook, the closed beta client is downloadable now. The CBT will begin on 26th June at 5:00 PM (UTC +2) with a unknown end date. The publisher expressed this closed beta test will last likely 2 to 5 weeks, depanding on the progresss during CBT.
Players could download client HERE. Players need an account to download the client. There are 2 download buttons, EU and NA. An important note is that they aren't related to each server, both distribute the same client which can let you play in the EU or NA server as you choose.
However in the download page those are just the mirror locations for the download, so if you're located within North America, you should go with the NA mirror for faster download performance!
As initially stated Inspirit Online will feature no IP blocks. However, during the ongoing dispute between the developers, this game has settled on not allowing Korean players only.
Once the CBT has finished, there will be a wipe of all characters and their data before continuing with OBT. That also includes account values such as the free distributed GCoins for testing. There will be no character and data wipe in the open beta test.