"The Box" is a frustratingly common title in the puzzle genre. Before you can solve "Level 100," you need to pinpoint exactly which game you are playing. There are at least five distinct possibilities, and the solution for one will not work for the others.
If you ask for help on a forum or Reddit, provide these four details:
Open YouTube and search: "[Exact Game Name] Level 100 Walkthrough" or "[Game Name] Level 100 Solution". For Bart Bonte games, the solution is often a specific trick (like the binary counter in Black or the button mash in Red). For The Room, look for a guide for the specific chapter and puzzle mechanism (e.g., "The Room Chapter 5 Lens Puzzle").