  The identification of the electromagnetic counterpart candidate ZTF19abanrhr
to the binary black hole merger GW190521 opens the possibility to infer
cosmological parameters from this standard siren with a uniquely identified
host galaxy. The distant merger allows for cosmological inference beyond the
Hubble constant. Here we show that the three-dimensional spatial location of
ZTF19abanrhr calculated from the electromagnetic data remains consistent with
the updated sky localization of GW190521 provided by the LIGO-Virgo
Collaboration. If ZTF19abanrhr is associated with the GW190521 merger and
assuming a flat wCDM model we find that $H_0 =48^{+24}_{-10}$ km/s/Mpc,
$\Omega_m =0.39^{+0.38}_{-0.29}$, and $w_0 = -1.29^{+0.63}_{-0.50}$ (median and
68% credible interval). If we use the Hubble constant value inferred from
another gravitational-wave event, GW170817, as a prior for our analysis,
together with assumption of a flat ${\Lambda}$CDM and the model-independent
constraint on the physical matter density ${\omega}_m$ from Planck, we find
$H_0 = 69.1^{8.7}_{-6.0}$ km/s/Mpc.
