For more control, such as a toggle key to turn brightness on and off, use a dedicated mod.
If you plan on submitting runs to official leaderboards, be aware that many categories forbid setting your gamma higher than 5.0. Minecraft FullBright with NO MODS Tutorial Fullbright 1.17
The Fullbright mod on Modrinth is a lightweight choice for 1.17. For more control, such as a toggle key
Press Win + R , type %appdata%\.minecraft , and hit Enter. Step 3: Find the options.txt file and open it with Notepad. For more control
FullBright UB is a widely used pack that removes all shadows.