“Also worth noting, the Ugaritic texts strongly support the interpretation of Genesis 6:1–4, where the “sons of God” (bene ha’elohim) are understood to be divine beings or angels, not human rulers or descendants of Seth.”
Or, one can just accept the wording as not needing intrepretation. The descendants of Seth concept is self-contradictory. According to Jude, there was some non-human sexual couplings going on in Sodom and Gomorrah.
I accept Gen 6 as it is, but many theologians don’t (for reasons that seem odd).