Hello, in the game, you can get the corresponding experience value by killing the enemy with weapons. Even killing people can gain more experience. When the experience value accumulates to a certain extent (see the corresponding weapon pattern on the right), you can get accessories when the blue progress bar is full. If the color of the weapon pattern is opaque, it means that the weapon has been upgraded and does not need to be upgraded. In addition, some weapons can be unlocked through customs clearance. You can carefully look for hidden weapons on the map. For example, you can get a Mao Se pistol on a university mission. (You can also choose the Mao Se pistol as the last task.) Weapons such as rocket launchers can only be found on maps or enemies:)