Hello! Please advise on a good expectorant (preferably syrup). For t…

Hello! Please advise on a good expectorant (preferably syrup). For three weeks now there has been phlegm in my throat and it comes out only in the morning (excuse me for the details), green colored, and my nose is stuffed up in the mornings. I went to an ENT doctor and a therapist who say everything is fine and nothing needs to be done. But I'm tearing at every day because the phlegm hangs and doesn't go anywhere. Is there any method of getting rid of the phlegm? Thanks in advance.