For Gym Star Simulator in Roblox, the inventory is usually opened with the I key on PC, or by tapping the inventory/backpack button if the game shows one on screen. A recent public post about the game specifically mentions holding or pressing I to get into inventory, and general Roblox tutorials confirm that many games also use a backpack icon or custom menu button.

Quick steps

  1. Join Gym Star Simulator.
  2. Press I on your keyboard.
  3. If nothing happens, look for a backpack , inventory , or three-dots/menu icon on the screen.
  4. On smaller keyboards or if the keybind is hidden, open the Roblox in-game menu and check for an inventory option.

If it still won’t open

  • The game may have a custom control layout.
  • Try clicking any Shop or menu button, since some Roblox games place inventory-related options there.
  • On mobile, inventory controls are often inside a menu rather than mapped to a keyboard key.

TL;DR

In Gym Star Simulator, try I first. If that fails, use the on-screen inventory/menu button because the game may override the default Roblox control.