To complete the last Meteoric Footprint hidden challenge, you'll need to touch a giant glowing cube, enter the rift above Loot Lake, and look for a landing pod inside a meteor. You will therefore have to go to three different points on the map where these places are.
Map made with Lootlake.info
It's easy for this challenge to visit all three points of interest in a single match. The recommended way to get there easily is to descend towards the meteorite to visit the landing capsule. The latter is inside, and you will have to interact with it for the challenge to be validated. Once that's done, all you have to do is jump down, head to Loot Lake, and take the rift there. All you have to do is fly, towards the cube of the flying island, in order to complete the challenge.
As a reminder, it's easier to complete this challenge in Team Rumble, then with respawning, you won't have to worry about dying.