When i open minecraft with your mod the game says this thing in the loading error section. I'm on the latest version of the mod in 1.16.5

It usually happens when Forge is not updated. Make sure the version listed in the changelog matches the version of Forge currently installed.

Ok so i checked and i have the 36.1.0 version of forge (a really old version). The latest version is the 36.2.9 but the recommended one is 36.2.0 (that also is newer than mine). Should i download the latest (36.2.9) or the recommended (36.2.0)?

ok i downloaded the recommended one and it worked. Thank you!