Is Sola Scriptura Important for the Basic Contexts of Christian Theology?

I'm curious, who is the earliest Christian to say their scripture is the only infallible rule of faith? If God wants us to know something is true, it'll be in the Bible. I won't try to recall the exact- Is Sola Scriptura important for the basic contours of Christian theology? Well, it's not really a doctrine. That's what I said earlier. It's more of a pro-logonal methodological matter.