Nudge Region/Event Length Right by 1/2 SMPTE Frame

Make the currently selected event or region longer by adding 1/2 of a SMPTE frame to the right side of the region.

Resize regions in Logic Pro — Apple Support

You can shorten both audio and MIDI regions so that only part of the region plays. You can lengthen MIDI regions to add silence to the beginning or end of the region. In addition, you can resize the common edge of two adjacent regions to control the transition between them and remove overlaps.