Blue Coin Challenge

Blue Coin Challenge is a Side Quest in Mario + Rabbids Sparks of Hope, located on all five planets.

Description
On each planet is a mechanical-looking blue Warp Pipe that houses a larger mechanical room containing a P-Switch. The Quest begins by activating it, making a set of Blue Coins appear for a limited time. Collecting all the Blue Coins in a set makes another set appear. Collecting all the Blue Coins from the last set completes the Quest and the player is rewarded with a Planet Coin from that planet, a treasure chest containing coins, and a Probe containing a Memory regarding that planet.

Beacon Beach
On the first floor of the Lighthouse, on the opposite side of the entrance.

Terra Flora
In Mt. Spout, near the Golden Pipe and the Darkmess Puddle for the Metalheads battle.