I simply used the mouse cursor. If you have it activated in your prefs, right clicking on the arrange page opens the tool box. While you have it open, hover over the pointer tool, left click on it while holding the right button and it gives you 3 options. The bottom option says “sizing applies time stretch”.
Click on that option and your pointer will now have a little clock attached. With that, you grab the little lower end box on the audio file and stretch to where you want. Use your snap function to have it precisely lock onto any bar.