Secret Course 23
From the Super Mario Wiki
Secret Course 23 is the twenty-third secret course that appears in the Remix 10 mode of Super Mario Run. This secret course takes place in the sky.
The course starts off with three ? Blocks each containing a Super Mushroom. This leads into a path with Mushroom Platforms and Fire Bars. The first Bonus Medal is underneath the first Fire Bar. The second Bonus Medal is found in between three more Fire Bars and the third Bonus Medal is immediately after it, right before another ? Block, which contains the fourth Bonus Medal. The path ends at a Springboard before the Goal Pole. The fifth and final Bonus Medal can be obtained by jumping up from the Springboard to above the Goal Pole.