  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 towards H$\alpha$,
$A_{\mathrm{H}\alpha}$, are derived. In both redshift bins, the integrated
Balmer Decrement increases with stellar mass. Lower mass
($7.6\leqslant$Log($M_{*}$/M$_{\odot}$)$<10.0$) galaxies have centrally
concentrated, negative dust attenuation profiles whereas higher mass galaxies
($10.0\leqslant$Log($M_{*}$/M$_{\odot}$)$<11.1$) have flat dust attenuation
profiles. The total dust obscuration is mild, with on average $0.07\pm0.07$ and
$0.14\pm0.07$ mag in the low and high redshift bins respectively. We model the
typical light profiles of star-forming galaxies at these redshifts and stellar
masses with GALFIT and apply both uniform and radially varying dust attenuation
corrections based on our integrated Balmer Decrements and radial dust
attenuation profiles. If these galaxies were observed with typical JWST NIRSpec
slit spectroscopy ($0.2\times0.5^{\prime\prime}$ shutters), on average,
H$\alpha$ star formation rates (SFRs) measured after slit-loss corrections
assuming uniform dust attenuation will overestimate the total SFR by $6\pm21
\%$ and $26\pm9 \%$ at $1.0\leqslant z < 1.7$ and $1.7\leqslant z < 2.4$
respectively.
