I thi k maybe it can be used in both ways, like " I cannot overstate the importance of this" or "you can not understate what I just said" cannot as in "I am not

I thi k maybe it can be used in both ways, like " I cannot overstate the importance of this" or "you can not understate what I just said" cannot as in "I am not allowing you to understate what I said". Idk, that's my most generous reading of it.