404 error on all sub pages

My home page is working fine, but all sub pages have started throwing 404 error.

Home page - mydemosales – Just another WordPress site (000webhostapp.com)

Sub pages - Page Not Found | 000webhost (000webhostapp.com)

Clearing cache doesn’t help

If this is WordPress you can visit WP-admin and then settings and permalinks and pick any option to resolve this.