In Roblox Rivals, the usual way to change the display or resolution is through the game’s settings gear and, if you want a stretched look, by changing your monitor resolution in Windows first, then matching it in-game.

What to do

  1. Open Rivals and click the settings gear in the hub/menu area.
  1. Check the game’s video and general settings for options like FOV, crosshair, and graphics, since those are the settings Rivals exposes directly.
  1. For a stretched display, change your Windows display resolution on the monitor you use for Rivals, then apply the same resolution in Roblox/Rivals.
  1. If you use an Nvidia GPU, some guides also use Nvidia Control Panel to set a custom resolution and apply it before launching the game.

What “display” may mean

If you mean your name instead of the screen, Rivals does not appear to have a separate in-game display name; players generally use their Roblox display name instead.

Quick note

A lot of recent tutorials for Rivals focus on settings, FOV, crosshair, and stretched resolution rather than a special “hotstar display” option, so I’m assuming you meant display/resolution settings.

TL;DR: Open Rivals settings for in-game options, but for stretched or different display size, change your PC monitor resolution first and then match it in the game.