I am not able to search music on Apple Music
not able to search music on apple music. can only listen to songs on my library
[Edited by Moderator]
This does not appear to be related to iTunes judging from your picture above and therefore not related to High Sierra as to where is posting is appearing.
The Music App was first introduced in macOS Catalina 10.15 and above
Below is a screen shot of Music on macOS Monterey version 12.5.1 and something is you pic is missing