Use the chart under Minecraft Version on the left to ensure you're downloading the version of Forge that corresponds with your current version of Minecraft and the mods you're running.

After Minecraft 1.21.6, many will look for the updated version of the mod. Hence, here is a short guide on downloading and installing Sodium for Minecraft 1.21.6.

With this guide you'll be able to install the Minecraft Pixelmon mod, which is essentially Pokemon in Minecraft.