Make sure you can install this composer.json locally

composer.json

{
  "require": {
    "php": "^7.3",
    "ext-pdo": "*",
    "ext-pdo_sqlite": "*",
    "ext-xdebug": "*",
    "ext-curl": "*",
    "ext-dom": "*",
    "ext-iconv": "*",
    "ext-json": "*",
    "ext-libxml": "*",
    "ext-mbstring": "*",
    "ext-openssl": "*",
    "ext-simplexml": "*",
    "ext-tokenizer": "*",
    "ext-xml": "*",
    "ext-xmlwriter": "*"
  }
}