Hi danial, I think you can flash uboot first, and then the use the uboot web to flash the firmware.
uboot file: uboot-for-qca95xx/uboot-gl-ar750-20180705-md5-447252d5073b4cdb5fa53252010a876a.bin at master · gl-inet/uboot-for-qca95xx · GitHub
art file: https://glinet-hoff-temp-file.oss-cn-shenzhen.aliyuncs.com/94_83_C4_0A_4F_FA-art.bin