CONTAINS SPOILERS

From the Main Path to the Creator's Tears, go left into the Beta Tesseract. The Toad provides the clue. Press the button outside to the left. Next, go far right into the Alpha Tesseract. The Priest provides the clue. Press the button outside to the right. Pressing both buttons gives you access to the Encrypted Access Portal for the final clue. Enter the symbols in order from left to right.