  The High Energy Stereoscopic System (H.E.S.S.) started observing the
extremely powerful long-duration gamma-ray burst, GRB 221009A, after 53 hours
of the triggering event. The H.E.S.S. collaboration carried out observations on
the 11, 12, and 17, of October 2022 under poor atmospheric conditions, without
detecting significant very high-energy photons from the source and computed the
upper limits of the fluxes for the different nights. We study these flux upper
limits by using the photohadronic model and show that the interaction of
high-energy protons with the synchrotron seed photons in the forward shock
region of the GRB jet exhibits behavior compatible with the upper limits
computed by the H.E.S.S. collaboration.
