NestJS factory pattern for use service

I have 2 types of login. I need to pass the param in the request and use this param in auth service to choose what service for login I should use.
Does mb exist better way?

Body in POST request.

{
    "type": "Customer",
    "store": "store24",
    "email": "test333333@email.com",
    "password": "testpass2"
}

authFactory.ts

const loginFactoryTypes = {
  [LOGIN_TYPE.Customer]: CustomerAuthService,
  [LOGIN_TYPE.User]: UserAuthService,
};

export const createLoginFactory = (type: string) => {
  return loginFactoryTypes[type];
};

auth.controller.ts

@Post('/signin')
signInFactory(@Body() signInDto: SignInUserDto & SignInCustomerDto): Promise<unknown> {
  const { type } = signInDto;

  const loginFactory: AuthInterface = createLoginFactory(type);

  return loginFactory.signin(signInDto);
}

If I pass param type - Customer then I get this service CustomerAuthService.

async signin(signInDto: SignInCustomerDto) {
  const customer = await this.customersService.findCustomerByEmail(signInDto);

  const token = this.jwtService.sign({
    id: customer.id,
    email: customer.email,
  });

  return { token, customer };
}

But the controller gets me an error on the string.
loginFactory.signin(signInDto);

I get the error loginFactory.signin is not a function.

as you have this:

const loginFactoryTypes = {
  [LOGIN_TYPE.Customer]: CustomerAuthService,
  [LOGIN_TYPE.User]: UserAuthService,
};

loginFactoryTypes[type] will return a class, not an instance like you've expected.

At the consumer side of createLoginFactory, you could leverage on moduleRef to retrieve an instance of that class using Nest's DI system.