firebase-js-sdk/packages/util/api-extractor.json

{
    "extends": "../../config/api-extractor.json",
    // Point it to your entry point d.ts file. 
    "mainEntryPointFilePath": "<projectFolder>/dist/index.d.ts",
    "dtsRollup": {
        "enabled": true,
        "untrimmedFilePath": "<projectFolder>/dist/<unscopedPackageName>.d.ts",
        "publicTrimmedFilePath": "<projectFolder>/dist/<unscopedPackageName>-public.d.ts"
    },
    "messages": {
      "extractorMessageReporting": {
        "ae-missing-release-tag": {
          "logLevel": "warning",
          "addToApiReportFile": true
        }
      },
      "tsdocMessageReporting": {
        "default": {
          "logLevel": "none"
        }
      }
    }
}