How do i connect my chromecast ultra to my Samsung Galaxy A5

[AC Question]

Chromecast ultra says it is connected to my phone wifi but it won't work

 

[B. Diddy]

Welcome to Android Central! Chromecast requires you to have a wi-fi network set up at home. Your Chromecast and your phone have to be both connected to the same wi-fi network. See here for more details: https://support.google.com/chromecast/chromecast/?hl=en#topic=3058948