{
  "name": "easybill/zugferd-php",
  "description": "..",
  "keywords": [
    "ZUGFeRD"
  ],
  "type": "library",
  "minimum-stability": "stable",
  "license": "MIT",
  "authors": [
    {
      "name": "Patrick Romowicz",
      "email": "patrick@romowicz.de"
    }
  ],
  "require": {
    "php": ">=5.4.0",
    "jms/serializer": "^1.7"
  },
  "require-dev": {
    "phpunit/phpunit": "^8"
  },
  "autoload": {
    "psr-4": {
      "Easybill\\ZUGFeRD\\": "src/Easybill/ZUGFeRD/"
    },
    "exclude-from-classmap": [
      "**/Tests/"
    ]
  }
}

{
  "name": "easybill/zugferd-php",
  "description": "..",
  "keywords": [
    "ZUGFeRD"
  ],
  "type": "library",
  "minimum-stability": "stable",
  "license": "MIT",
  "authors": [
    {
      "name": "Patrick Romowicz",
      "email": "patrick@romowicz.de"
    }
  ],
  "require": {
    "php": "^7.2",
    "jms/serializer": "^1.7"
  },
  "require-dev": {
    "phpunit/phpunit": "^8"
  },
  "autoload": {
    "psr-4": {
      "Easybill\\ZUGFeRD\\": "src/Easybill/ZUGFeRD/"
    },
    "exclude-from-classmap": [
      "**/Tests/"
    ]
  }
}

Change require php version to ^7.2
Change require php version to ^7.2
