Unable to read/reference from different entity variable value

I am trying to create a custom entity that rotates in the same way the player is rotating in real-time by reading query.body_y_rotation of the player and set this value in the animation of the custom entity to make it look like rotating the same way the player is rotating

I read from Bedrock.dev website that if I want to read/reference a variable value from a different entity, I have to use the [->] Arrow Operator but the article was not clear enough to show me how exactly to use it. It said that I need to set the variable value that I want to reference to PUBLIC, which I already did. Then to use the [->]  ** arrow operator symbol in a different entity to read that public variable which I did but was not sure if it was the right way because it is not clear in the article how to use it. After I finished and launched Minecraft windows to try the code, it didn't work at all and the content log in Minecraft throw this error:-

[Molang][error]-addon:entity_test | Error: unhandled request for unknown variable 'variable.player_y_rotation'

It means that the entity is not reading that public variable value. I had tried for about 4 days and searched on the internet for solutions or similar problems but I found nothing. There is nothing about how to access/read other entity variable values from a different entity. I need to know how, to complete my add-on.