Trimming 30 second ringtone in GarageBand on iPhone 13

I Am Having iPhone 13.I Am Downloading Songs From YouTube To Siri And To GarageBand.I Am Editing Ringtone In GarageBand For 30Seconds,On The Bars Of GarageBand.When I Play.It’s Like 13 to 17 Seconds Only.Not Sure Y It Is So Or What Shall I Do To Get Trimmed 30Seconds Of Ringtone.

•Please Advise.I Will Be Thankful To You.

[Re-Titled by Moderator]

Original Title: About Ringtone