Depois de incluir user.service " setToken(authToken)" não compila da o seguinte erro: ERROR

src/app/core/auth/auth.service.ts:28:39 - error TS2345: Argument of type 'string | null' is not assignable to parameter of type 'string'. Type 'null' is not assignable to type 'string'.

28 this.userService.setToken(authToken); ~

                                     ![](![auth.service](https://cdn1.gnarususercontent.com.br/1/927603/e2eda7ce-ccb4-469a-85de-b6e309bf4854.png)  ) ;



                                     ![token.service](https://cdn1.gnarususercontent.com.br/1/927603/6bec6bce-754f-4b86-8549-cce06b805a52.png)  


                                     ![user.service](https://cdn1.gnarususercontent.com.br/1/927603/cd602482-f035-426a-a5a3-991393970adc.png)