Unabsorbed X-ray luminosity of SN 2024iss observed in the 3–10 keV band. The red, green, and blue data points represent the observations conducted with NuSTAR, Swift-XRT, and EP-FXT, respectively. The black line shows the best-fit thermal bremsstrahlung model, with a mass-loss rate of 1.6 × 10⁻⁵ M_⊙ yr⁻¹ and a shock velocity of 9.5 × 10⁸ cm s⁻¹. The green and purple shaded areas indicate the 3σ and 5σ confidence regions, respectively.