A method, comprising: at an electronic device with a display device: displaying, via the display device, a user interface for a third-party application, wherein the user interface for the third-party application includes an affordance for setting up an account for the third-party application using a first-party authentication provider; receiving a request, corresponding to the affordance, to set up the account for the third-party application; in response to receiving the request to set up the account for the third-party application, displaying, via the display device, a user interface for first-party authentication, wherein the user interface for first-party authentication includes concurrently displaying: a first login option; and a second login option; detecting a set of one or more inputs; and in response to detecting the set of one or more inputs: in accordance with a determination that the set of one or more inputs corresponds to selection of the first login option that is concurrently displayed with the second login option, transmitting a request to use first contact information for a user to set up the account for the third-party application; and in accordance with a determination that the set of one or more inputs corresponds to selection of the second login option that is concurrently displayed with the first login option, transmitting a request to use second contact information for the user to set up the account for the third-party application, wherein the second contact information is automatically generated for the third-party application and does not reveal the first contact information for the user to the third-party application. displaying, via the display device, a user interface for a third-party application, wherein the user interface for the third-party application includes an affordance for setting up an account for the third-party application using a first-party authentication provider; receiving a request, corresponding to the affordance, to set up the account for the third-party application; in response to receiving the request to set up the account for the third-party application, displaying, via the display device, a user interface for first-party authentication, wherein the user interface for first-party authentication includes concurrently displaying: a first login option; and a second login option; a first login option; and a second login option; detecting a set of one or more inputs; and in response to detecting the set of one or more inputs: in accordance with a determination that the set of one or more inputs corresponds to selection of the first login option that is concurrently displayed with the second login option, transmitting a request to use first contact information for a user to set up the account for the third-party application; and in accordance with a determination that the set of one or more inputs corresponds to selection of the second login option that is concurrently displayed with the first login option, transmitting a request to use second contact information for the user to set up the account for the third-party application, wherein the second contact information is automatically generated for the third-party application and does not reveal the first contact information for the user to the third-party application. in accordance with a determination that the set of one or more inputs corresponds to selection of the first login option that is concurrently displayed with the second login option, transmitting a request to use first contact information for a user to set up the account for the third-party application; and in accordance with a determination that the set of one or more inputs corresponds to selection of the second login option that is concurrently displayed with the first login option, transmitting a request to use second contact information for the user to set up the account for the third-party application, wherein the second contact information is automatically generated for the third-party application and does not reveal the first contact information for the user to the third-party application.