How to roll dodge with the dual Guns

Since I own the German version I don't know how it is called in English, but when you stand in front of the building where the Salmon Run is played, you will find a counter to the left of it. There you can pick up your prizes.

In order to unlock the hero weapons for use in PvP you must go through Octo Canyon and complete every single mission and boss with the weapon you wish to unlock. For example if you want to get the Hero Dual Splats, you need to complete every mission and boss with the Dual Splats. After you complete all of the levels with the weapon you will unlock the weapon for use in PvP.

There is one weapon though that you are unable to unlock right now which is the Hero Brella weapon. When you complete all the levels with the Brella Sheldon will mention that he is still working on this one. Once Nintendo releases the Umbrella weapons the Hero Brella should be unlocked.