Title

You have to find this yourself, could also be the name of the song file.
Artist

Go to the album you want to add this song to -> click on the 3 dots -> properties -> copy the text under artist if your song has any more artists add them with a , between each one
Album

Go to the album you want to add this song to -> click on the 3 dots -> properties -> copy the text under album
Album Artist

Go to the album you want to add this song to -> click on the 3 dots -> properties -> copy the text under album artist
Year

Go to the album you want to add this song to -> click on the 3 dots -> properties -> copy the number under year
Track

Go to the album you want to add this song to -> click on the 3 dots -> properties -> take the number after track- of and add 1 to it
Total Tracks

Go to the album you want to add this song to -> click on the 3 dots -> properties -> copy the number after track- of without modifying it
Discnumber

Go to the album you want to add this song to ->if the album is sectioned then chose the section number you want to put it inif the album is not sectioned put 1
Total Discs

Go to the album you want to add this song to ->if the album is sectioned then put the number of sectionsif the album is not sectioned put 1
Genre

Go to the album you want to add this song to -> click on the 3 dots -> properties -> memerize the text under genre -> go back to mp3tag and write it exactly how it was in apple music
Composer

You have to add this yourself, just put the real name of the artist/s, producer/s, writer/s, each one seperated with ,
Date Modified

Go to the album you want to add this song to -> go to the last song -> right click on it -> properties -> go to the file tab -> copy the text after date modified
Date Added

Go to the album you want to add this song to -> go to the last song -> right click on it -> properties -> go to the file tab -> copy the text after date added

Go to the album you want to add this song to -> go to the last song -> right click on it -> properties -> go to the file tab -> copy the text after copyright
Bitrate

Put the bit rate of your song, can be found by clicking on properties on the file in file explorer
Audio Formats

Must be Dolby Atmos, Lossless, AAC
Cloud Status

Must be Apple Music
Location

Must be Cloud
Kind

Must be Apple Music AAC audio file
ITUNESADVISORY

Put0 if your song is clean
1 if your song is explicit