Transmission spectrum of TOI-2136 around the He triplet. The blank region is where we mask the strongest OH⁻ emission. The red line is contaminated by the other shallower OH⁻ emission lines. The orange line is the best-fitted model with a Gaussian function. Vertical green dashed lines indicate the center of the predicted He triplet in air, and the horizontal blue lines are standard deviations between 10820 and 10840 Å.