How to change default title in client login screen using Keycloak?

In your realm settings > HTML Display name

replace:

<div class="kc-logo-text"><span>Keycloak</span></div>

with your Application name that you wish to show on your login screen. you can also provide HTML code for using image instead of title

use

<img alt="..ALT-TEXT.." src="../../SOURCE" width="400"/> 

to insert your logo instead

Happy Hacking..