problem description

installing ubuntu18.04LTS, on macbbok shows an error near the end of the installation and is not seen clearly. Then call for restart, and enter the grub2 interface after reboot. I didn"t install ubuntu on my computer"s own hard drive. I installed it on Transcend external ssd. I don"t know if this will affect the installation.

the platform version of the problem and what methods you have tried

the computer is the annual version of Macbook Pro15 with Ubuntu18.04LTS "s ISO installed. Try to use the ls method to enter each partition to find boot, but it all shows the same content.

related codes

figure 1 shows the GNU GRUB interface entered after boot
figure 2 shows the partition of my computer after entering ls. I don"t know why there are so many such error
figure 3 shows this after entering ls (hd5, 0) / grub, and no matter which partition is entered, it is the same result

ask for help! Thank you!