if you haven't decided to pay for spotify Premium, you can execute this applescript on your mac to Mute Spotify Advertisements and unmute Spotify when playing your fav musics automatically.

spotifyAdAutoMute.scpt

global check_every, adDuration

set check_every to 20
set adDuration to 31000

display dialog "Start to Check AD of Spotify every " & check_every & " seconds."

on reopen
	display dialog "Start to Check AD of Spotify every " & check_every & " seconds."
end reopen

repeat while (application "Spotify" is running)
	
	tell application "System Events"
		set num to count (every process whose name is "Spotify")
	end tell
	
	if num > 0 then
		tell application "Spotify"
			set playState to (player state as text)
			if playState is equal to "playing" then
				set trackName to name of current track
				set artistName to artist of current track
				set albumName to album of current track
				set trackDuration to duration of current track
				set trackInfo to trackName & " | " & artistName & " | " & albumName & " | " & trackDuration
				
				if trackName is equal to "Spotify" or trackDuration is less than adDuration then
					set volume with output muted
				else
					set volume without output muted
				end if
			else
				set trackInfo to "Nothing playing"
			end if
			do shell script "echo " & quoted form of trackInfo & " > $HOME/Desktop/Test.txt"
		end tell
	else
		set trackInfo to "Nothing playing"
		do shell script "echo " & quoted form of trackInfo & " > $HOME/Desktop/Test.txt"
	end if
	
	delay check_every
end repeat