You can easily mix our protein ice cream with water in the shaker for 30 seconds. But, of course, it also works with milk or a milk alternative from oats, soybeans, etc. This makes the ice even creamier. Note, that this, however, changes the nutritional value.
Just put the ice cream mix in the popsicle mold and pop it in the freezer. One package is around 8 popsicles if you use the mold. Or experiment with a bowl, an ice cube tray, or any other container you can think of.