The protonated form of CO2, HOCO+, is assumed to be an indirect tracer of CO2 in the millimeter/submillimeter regime since CO2 lacks a permanent dipole moment. Here, we report the detection of two rotational emission lines (40, 4-30, 3 and 50, 5-40, 4) of HOCO+ in IRAS 16293-2422. For our observations, we have used EMIR heterodyne 3 mm receiver of the IRAM 30m telescope. The observed abundance of HOCO+ is compared with the simulations using the 3-phase NAUTILUS chemical model. Implications of the measured abundances of HOCO+ to study the chemistry of CO2 ices using JWST-MIRI and NIRSpec are discussed as well.