This was the contents of the bin/targets folder after I compiled the image. I’ll try again today to see if I can flash using the other files, but haven’t had much luck.
sestra-mini-0.1-ath79-nand-device-glinet-gl-ar300m-nand.manifest
sestra-mini-0.1-ath79-nand-glinet_gl-ar300m-nand-initramfs-kernel.bin
sestra-mini-0.1-ath79-nand-glinet_gl-ar300m-nand-squashfs-factory.img
sestra-mini-0.1-ath79-nand-glinet_gl-ar300m-nand-squashfs-sysupgrade.tar