Pipeline to setup EKS with terraform on bitbucket

bitbucket-pipelines.yml

image: atlassian/default-image:2

pipelines:
  # By default (master branch) only validation is going to be triggered
  default:
    - step:
        deployment: test
        name: EKS Infra build and validate
        script:
          - mkdir -p ~/bin
          - cd ~/bin
          - export PATH="$PATH:/root/bin"
          - apt-get update && apt-get install -y unzip python-pip
          
          - wget https://releases.hashicorp.com/terraform/0.11.13/terraform_0.11.13_linux_386.zip
          - unzip terraform_0.11.13_linux_386.zip
          - cd ${BITBUCKET_CLONE_DIR}
          - terraform version
          - terraform init
          - terraform show
          - terraform plan
  branches:
    # If a code is merged to branch tf-apply, it will execute below steps including terraform apply
    tf-apply:
      - step:
          name: Infra launch
          script:
            - mkdir -p ~/bin
            - cd ~/bin
            - export PATH="$PATH:/root/bin"
            - wget https://releases.hashicorp.com/terraform/0.11.13/terraform_0.11.13_linux_386.zip
            - unzip terraform_0.11.13_linux_386.zip
            - cd ${BITBUCKET_CLONE_DIR}
            - terraform version
            - terraform init
            - terraform apply -auto-approve
            #- terraform destroy -auto-approve
            - mkdir -p auth
            - terraform output config_map_aws_auth > auth/$AUTH_CM_FILE
            - pipe: atlassian/aws-s3-deploy:0.2.4
              variables:
                AWS_ACCESS_KEY_ID: $AWS_ACCESS_KEY_ID
                AWS_SECRET_ACCESS_KEY: $AWS_SECRET_ACCESS_KEY
                AWS_DEFAULT_REGION: $AWS_DEFAULT_REGION
                S3_BUCKET: $KUBE_CONFIG_CM_BUCKET
                LOCAL_PATH: $BITBUCKET_CLONE_DIR/auth
            

You don't seem to install the aws-cli tools, is there a specific reason? How can Terraform connect itselt to AWS?