Hello -  The DM at my table gave us a dagger that does 1d4 physchic damage, but no physical damage. Odd, I know, but it is what he intended. How can I create this? I cannot find a way to change the damage type a dagger does, and I cannot make a wonderous item show up as an attack. Another work-around I tried was to create a dagger and just get rid of any bonus to hit and deal with the fact that the damage type is listed wrong in the attack, but have that info in the description, I couldn't figure out how to do that either, Can someone help me with this? Thanks!

You cannot change the damage type on a regular dagger on the character sheet. You will have to create a magic item in the home reset: (https://www.dndbeyond.com/homebrew/creations/create-magic-item). Set it up basically as in the images below, but with any adjustments necessary. For example, if it’s sposta require attainment or anything you’ll need to add those details.

Do you have a rogue in the party with the soul knife subclass if so I think your DM don't like him or you have a barbarian your gonna go up against