Update POST.md

fixed broken identity module link

docs/en/Community-Articles/2020-04-19-Customize-the-SignIn-Manager/POST.md

@@ -1,6 +1,6 @@
 # How to Customize the SignIn Manager for ABP Applications
 
-After creating a new application using the [application startup template](https://docs.abp.io/en/abp/latest/Startup-Templates/Application), you may want extend or change the default behavior of the SignIn Manager for your authentication and registration flow needs. ABP [Account Module](https://docs.abp.io/en/abp/latest/Modules/Account) uses the [Identity Management Module](https://docs.abp.io/en/abp/latest/Modules/Identity) for SignIn Manager and the [Identity Management Module](../Modules/Identity.md) uses default [Microsoft Identity SignIn Manager](https://github.com/dotnet/aspnetcore/blob/master/src/Identity/Core/src/SignInManager.cs) ([see here](https://github.com/abpframework/abp/blob/be32a55449e270d2d456df3dabdc91f3ffdd4fa9/modules/identity/src/Volo.Abp.Identity.AspNetCore/Volo/Abp/Identity/AspNetCore/AbpIdentityAspNetCoreModule.cs#L17)). 
+After creating a new application using the [application startup template](https://docs.abp.io/en/abp/latest/Startup-Templates/Application), you may want extend or change the default behavior of the SignIn Manager for your authentication and registration flow needs. ABP [Account Module](https://docs.abp.io/en/abp/latest/Modules/Account) uses the [Identity Management Module](https://docs.abp.io/en/abp/latest/Modules/Identity) for SignIn Manager and the [Identity Management Module](https://docs.abp.io/en/abp/latest/Modules/Identity) uses default [Microsoft Identity SignIn Manager](https://github.com/dotnet/aspnetcore/blob/master/src/Identity/Core/src/SignInManager.cs) ([see here](https://github.com/abpframework/abp/blob/be32a55449e270d2d456df3dabdc91f3ffdd4fa9/modules/identity/src/Volo.Abp.Identity.AspNetCore/Volo/Abp/Identity/AspNetCore/AbpIdentityAspNetCoreModule.cs#L17)). 
 
 To write your Custom SignIn Manager, you need to extend [Microsoft Identity SignIn Manager](https://github.com/dotnet/aspnetcore/blob/master/src/Identity/Core/src/SignInManager.cs) class and register it to the DI container.