Hello and Welcome To BYC! Most chickens are pretty trainable using treats / food to get them to come back in to a run. Scratch is easy to use for that, just have a can that you shake and call them, they will get used to the noise / your call meaning scratch is going to be available and will come running. Start training them in the run, then let them out for a little bit right before bed time when they will normally come in anyhow, and pretty soon they will come from anywhere.
X 2 on what Kelsie suggests. Make a consistent sound when you feed them so that they become habituated to that sound and the appearance of feed. When you free range, let them out unfed, and then use the sound and feed to lure them back to their pen.
The way a chicken's heart is through their stomach - you don't even need to shake a can use a special call to announce you have something - Like Hey chicks or Treats, treats, just be consistent they learn fast.