How to make the audio longer in Adobe Animate

Hello.
I have a problem with the sound in Adobe Animate. I have a sound clip on 8 minutes and I have improted it to the stage but right now it's only one minute long because I've dragged the frames. Is there a faster way to make the sound clip longer than just dragging the keyframe? Or is there a way to import the sound and then it's 8 minutes right away? I hope you can help.