  We present the results of direct-method metallicity measurements in the disk
and outflow of the low-metallicity starburst galaxy NGC 1569. We use Keck
Cosmic Web Imager observations to map the galaxy across 54$\arcsec$ (800 pc)
along the major axis and 48$\arcsec$ (700 pc) along the minor axis with a
spatial resolution of 1$\arcsec$ ($\sim$15 pc). We detect common strong
emission lines ([\ion{O}{III}] $\lambda$5007, H$\beta$, [\ion{O}{II}]
$\lambda$3727) and the fainter [\ion{O}{III}] $\lambda$4363 auroral line, which
allows us to measure electron temperature ($T_e$) and metallicity. Theory
suggests that outflows drive metals out of the disk driving observed trends
between stellar mass and gas-phase metallicity. Our main result is that the
metallicity in the outflow is similar to that of the disk, $Z_{\rm out} /
Z_{\rm ISM} \approx 1$. This is consistent with previous absorption line
studies in higher mass galaxies. Assumption of a mass-loading factor of
$\dot{M}_{\rm out}/{\rm SFR}\sim3$ makes the metal-loading of NGC 1569
consistent with expectations derived from the mass-metallicity relationship.
Our high spatial resolution metallicity maps reveal a region around a
supermassive star cluster (SSC-B) with distinctly higher metallicity and higher
electron density, compared to the disk. Given the known properties of SSC-B the
higher metallicity and density of this region are likely the result of star
formation-driven feedback acting on the local scale. Overall, our results are
consistent with the picture in which metal-enriched winds pollute the
circumgalactic medium surrounding galaxies, and thus connect the small-scale
feedback processes to large-scale properties of galaxy halos.
