God is the "author" of our faith (Heb. 12:2), i.e. the founder, the originator. He has prepared good works for his people to do (Eph. 2:10).
By contrast, Scripture does not say God is the "author" (originator) of sin, nor does it say God has created evil works for the reprobate to walk in. There's no divine work of "anti-sanctification" in the reprobate to parallel the work of sanctification in the elect.
We can infer that if God ordains everything that comes to pass, he has done so in a way that the reprobates freely choose to commit their sins of their own volition, not because he has commanded or encouraged their sins, or participated in them.
God "intended" that Joseph be sold into slavery (Gen. 50:20). He used the evil of Joseph's brothers to put Joseph in Egypt at the right time and place to preserve life, and ultimately to build his chosen people into a nation. Does that mean God was the author of his brothers' sins? No, it means he let them sin.