If you ever run `composer install` and terminal hands and then shows `killed` it means the server does not have enough memory to install the packages, this is common if you do not have a composer.lock file in the repository.
IF you do not have a `composer.lock` file in your respositoy then should:
ensure `compoer.lock` is not in a `.gitignore` file Run `composer install` in a local environment (either your local physical machine, or a development virtual machine)
With the updated `composer.lock` file commit the file and push it to your repository.
Then on the server `git pull` and then you should be able to do a `composer install` using the same versions as you've done locally.