Whenever I try to use this mod in 1.16.5, when Minecraft loads it says that the mod is for 1.18.1 when it is not. I have tried multiple versions of the mod but every time it says this.

Show us a screenshot of your mods folder.

Well, I pinpointed the problem. In the download area, they don't have blueprint mod for 1.16.5 but they do have the abnormals core in the blueprint mod download section. Does blueprint get included with abnormal core for 1.16.5?

Abnormals Core was renamed Blueprint.

abnormals_core-1.16.5-3.3.0

But I have also tried the newest version and an older version.

What is the name of the file you have installed