Music and lyrics published in 1922 or earlier are in the public domain in the USA.
No one can claim ownership of a song in the public domain, therefore public domain songs can be freely used with no fees or royalties payable to anyone.
However it is important to remember that there are "performance rights", which must be paid to any performer of the song (orchestra, ensemble, musician, etc.).
Therefore make sure that the version of the track in your possession also respects the related rights of execution.
Once you have ascertained that the song is actually in the public domain, check the corresponding box ("The audio and the music are in the public domain. I enclose proof of this.") in the copyright sheet and remember to attach the proof (screenshot, e-mail, document ...) that confirms it is.