You can tile a 2 × 2 × 5 grid as follows.

Stacking three of these vertically gives the desired tiling.
Update: the OP clarified in the comments below that all 12 pentacubes must be different. Here’s one way to do this. First, I’ll borrow @PebNischl’s answer to make a 2 × 2 × 5

Next, I can make the following shape.

This can be combined with its mirror image (which has J2 and N1) to make another 2 × 2 × 5. Finally, I can make the last shape above in a different way.

Once again, this can be combined with its mirror image (which has J4 and V1) to make another 2 × 2 × 5. Combining all the shapes gives a 2 × 2 × 15 with twelve different pentacubes.