Roblox has no native Linux client. The current, actively-maintained way to run it is Sober (from the Vinegar project) - a Flatpak that runs the real Roblox client through a purpose-built Wine layer, rather than a generic Wine prefix.
pearOS NiceC0re (Arch-based)
Flatpak isn't installed by default - set it up first:
sudo pacman -S flatpak
flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
flatpak install flathub org.vinegarhq.Sober
pearOS Goldwing (Debian-based)
Flatpak and the Flathub remote are already set up by default - just install it:
flatpak install flathub org.vinegarhq.Sober
On either build: launch Sober from the app menu, log into Roblox as usual. It needs a working Vulkan-capable GPU driver - if it fails to start, check your GPU driver article first (NVIDIA especially needs the proprietary driver, not nouveau).