But gd install is missing.
Have you tried installing GD?
I have no experience with Amazon but found these kind of commands when Googling for Amazon php-gd:
sudo yum install php-gd
or
php --version
// the answer is something in the form PHP X.Y.Z
sudo yum install phpXY-gd
bin/gpm works.
A few hours earlier you created the post Error grav running on aws lightsail. Does this post mean you have Grav running at the moment (apart from the GD error)? If so, would you mind creating a reply to your post with the answer to your own question? And then mark your reply as “Solution”?