firebase-js-sdk/packages/app-compat/api-extractor.json

{
    "extends": "../../config/api-extractor.json",
    // Point it to your entry point d.ts file. 
    "mainEntryPointFilePath": "<projectFolder>/dist/src/index.d.ts",
    "dtsRollup": {
        "enabled": true,
        "untrimmedFilePath": "<projectFolder>/dist/<unscopedPackageName>.d.ts",
        "publicTrimmedFilePath": "<projectFolder>/dist/<unscopedPackageName>-public.d.ts"
    },
    "apiReport": {
        /**
         * only dts rollup is needed for app-compat
         */
        "enabled": false
    }
}