Press and hold the trackpad with one finger, then move your finger to drag
Tap and drag with one finger if Tap to Click and Drag Lock are enabled
Click and hold with one finger, then slide to move the item
Use two fingers to drag if Three Finger Drag is enabled in Trackpad settings
Enable Three Finger Drag in System Settings > Trackpad > Point & Click > Three Finger Drag
Use an external mouse: click and hold the button, then move the mouse to drag
Release the click or lift your finger to drop the item