[Home](./index.md) > [@firebase/auth-types](./auth-types.md) > [PhoneMultiFactorGenerator](./auth-types.phonemultifactorgenerator.md) ## PhoneMultiFactorGenerator class Provider for generating a [PhoneMultiFactorAssertion](./auth-types.phonemultifactorassertion.md). Signature: ```typescript export abstract class PhoneMultiFactorGenerator ``` ## Properties | Property | Modifiers | Type | Description | | --- | --- | --- | --- | | [FACTOR\_ID](./auth-types.phonemultifactorgenerator.factor_id.md) | static | [ProviderId](./auth-types.providerid.md) | The identifier of the phone second factor: [ProviderId.PHONE](./auth-types.providerid.phone.md). | ## Methods | Method | Modifiers | Description | | --- | --- | --- | | [assertion(phoneAuthCredential)](./auth-types.phonemultifactorgenerator.assertion.md) | static | Provides a [PhoneMultiFactorAssertion](./auth-types.phonemultifactorassertion.md) to confirm ownership of the phone second factor. |