I can roll 20 on d20 and have +4 dexterrity bonus + 3 proficiency +4 Guidance on d4, so the result will be 31. Low probability but possible. Just want to see actual difficulty level
Yes, I understand.
That is not what that screen shows you.
I agree it is daft, but the way this screen works, is it takes, the difficulty of the steal, reduces it by your modifiers, and then shows you the "required roll of a d20".