Converting Flac to M4a, to sync to Applemusic

Hi guys, i have a huge FLAC library from a friend, and i just learned about adding my own music to  music, from what i learned sofar:

I used FOOBAR2000 to convert my FLAC files into Apple Lossless and i find the files are .M4a, and then sync it through iTunes,

Am i missing something?