If you are using a Pi (Raspberry Pi OS), the standard firmware-realtek package often fails. You need to compile manually:
The is a widely used, budget-friendly Wi-Fi adapter designed to provide wireless connectivity to desktops and laptops that lack internal cards. Operating on the 2.4 GHz band , it supports the IEEE 802.11n standard with theoretical speeds of up to 150 Mbps . Key Specifications and Features
: Install building tools using sudo apt install build-essential git dkms .
The Realtek 8188GU is notorious for having poor out-of-the-box support on Linux kernels older than 5.15. You usually need to compile the driver from source.