Comparison of the stellar mass-metallicity relation predicted by our best-fitting models (black star for NGC 7793, red triangle for NGC 2403, blue square for NGC 300, magenta diamond for M 33, and green pentagon for NGC 5194) with that published in the literature. The solid circles show the stellar metallicity of nearby galaxies measured from spectroscopy of individual blue supergiants (cyan), red supergiants (pink), and super star clusters (yellow; see Bresolin et al. 2022, reference therein). The thin orange diamonds are the MZR derived from the young stellar population of SDSS star-forming galaxies (Sextl et al. 2023).