How do I rotate armatures with code using Forward Kinematics

I have heard of Inverse Kinematics but I want I want to do things the other way. Most of the examples use things that I do not need. I would just like to build some kind of function that rotates the armatures that I need.

Rotate the whole thing?
You just rotate the root bone.

Rotate parts? You just add a modify bone node with an exposed rotator pin.

Forward kinematics isn’t a thing, it’s just how stuff works Normally - so its not hidden or complex, it just works like that out of the box.

IK is taking an end point and calculating where the rest of the bones have to be to allow for that position - while taking into account limits so as not to distort the skeleton.
This is applicable to humanoids and organics which are prone to unnatural movements.

When making robots and such its a non issue since you can move articulations pretty much any way you want without it looking bad - maybe with the exception of self collision being needed.

Explain what your end goal is, with examples, you’ll get better answers.

I could use some documentation for this. What I want is to be able to train a character to walk so that I could create a natural movement myself. I know that this is a strange way of doing things. I am quite new so I am looking to do this first then I would have something I could work with to move my character.

Nothing works the way you think.

Start with doing 3d animation in a 3d program. There’s plenty of tutorials put there ready made for the software of your choice.
Go from there.
You’ll get to know why IK rigs matter.