Flatpak not installing any app

for every app its showing
Looking for matches…
error: No remote refs found similar to ‘<app_name>’

i tried using
flatpak search vlc
No matches found

and also tried the command from clear linux appstore
Looking for matches…
error: No remote refs found similar to ‘flathub’

its fresh install
did i need to do some more configurations

This should have been set automatically with clr-desktop-defaults.

You can manually do it with:
flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo