How to get the default theme of manjaro 20 in the latest manjaro 21.1.5?

manjaro 20 theme was the best theme. can anyone teach me how to get that theme back? new manjaro has all rounded edge. hate it

Are you speaking default themes?
Of what flavour? XFCE? KDE? Gnome?
In any case you can install and switch themes at will - your desktop will have a utility/setting for applying them.