We present the first results on the spatial distribution of dust attenuation at 1.0 < z < 2.4 traced by the Balmer decrement, H alpha/H beta, in emission-line galaxies using deep JWST NIRISS slitless spectroscopy from the CAnadian NIRISS Unbiased Cluster Survey (CANUCS). H alpha and H beta emission-line maps of emission-line galaxies are extracted and stacked in bins of stellar mass for two grism redshift bins, 1.0 < z (grism) < 1.7 and 1.7 < z (grism) < 2.4. Surface brightness profiles for the Balmer decrement are measured and radial profiles of the dust attenuation toward H alpha, A (H alpha ), are derived. In both redshift bins, the integrated Balmer decrement increases with stellar mass. Lower-mass (7.6