BPT diagram for our sample of extremely low-metallicity galaxies. Blue circles show galaxies with detected N II]λ6584 line, while blue triangles represent galaxies with S/N < 3 in N II]λ6584. Gray circles represent the entire sample of DESI galaxies with z < 0.5. The solid line is the theoretical upper limit for star-forming galaxies presented by Kewley et al. (2001). The dashed line is the demarcation line proposed by Kauffmann et al. (2003) as a lower limit for the area of AGNs.