Custom login page in VBCS and using REST API.

Summary:

I'm using the rest API to verify the username and password. If I entered the correct username and password it is working fine and navigate to the home page. but if I entered the wrong password. it shows the below mentioned error I have also attached the demo application.

I wish to display a simpler error message "incorrect user credentials" or ''Please enter the correct password".

Can anyone guide me where I'm wrong.

Username:- zi1159

Password:- abc@123

Thanks

Pawanjit Kaur