I have below code

stages:
  - build

variables:
  TARGET:
    description: "Select target (ABC, XYZ)"
    value: "none"
    options:
      - none
      - ABC
      - XYZ

  ENABLE_ABC: "0"
  ENABLE_XYZ: "0"

before_script:
  - echo "Selected target: $TARGET"
  - |
    if [ "$TARGET" == "ABC" ]; then
      export ENABLE_ABC="1"
    elif [ "$TARGET" == "XYZ" ]; then
      export ENABLE_XYZ="1"
    fi
  - echo "Enable ABC: $ENABLE_ABC"
  - echo "Enable XYZ: $ENABLE_XYZ"

build:
  stage: build
  script:
    - echo "Selected target: $TARGET"
    - >
      if [ "$ENABLE_ABC" == "1" ]; then
        echo "ABC target is enabled"
      fi
    - >
      if [ "$ENABLE_XYZ" == "1" ]; then
        echo "XYZ target is enabled"
      fi

I try to use option(TARGET) or directly with api trigger to enable both ENABLE_* to control this pipeline, but I always got
“before_script config should be a string or a nested array of strings up to 10 levels deep”