Roboto Serif / 400
{
  "copyright": {
    "en": "Copyright 2020 The Roboto Serif Project Authors (https://github.com/googlefonts/RobotoSerif)"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}

Roboto Serif / 600
{
  "copyright": {
    "en": "Copyright 2020 The Roboto Serif Project Authors (https://github.com/googlefonts/RobotoSerif)"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}

Roboto Serif / 700
{
  "copyright": {
    "en": "Copyright 2020 The Roboto Serif Project Authors (https://github.com/googlefonts/RobotoSerif)"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}