Romans 5:13

¹³ (For until the law sin was in the world, but sin is not imputed when there is no law.

Imputed = put to account, lay to one’s charge

Between Adam and Moses, sin wasn’t a transgression of the law because there was no law, but death still reigned because of Adam’s sin and that sin was passed to all — even to those who hadn’t disobeyed a command of God, as Adam did.