To get started, watch this video:
Now, imagine that your local mad scientist has created an extremely sophisticated robot. This robot has consciousness, intelligence, and indeed all the characteristics of a human mind except (possibly) one. The robot (may or may not) lack free will. The mad scientist wants the robot to have free will, and asks for your help in (possibly) altering the robot so that it has free will. Your assignment is to figure out what mechanism, or way of being, is necessary in order for something to have free will.
Remember, it may turn out to be the case that the robot already has free will, and the scientist, for some reason, hasn't noticed or realized that they have already created a free-willed robot.
For reference, remember that the existence of free will means that an entity has a "will", which is an internal faculty of being able to decide for itself what it is going to do, based on it's own ideas and goals, and that it also occasionally has the freedom to act on its own decisions, rather than being coerced by some external force to do things it would not, on its own, decide to do. (Added 3/14/23.)
If you accept that it is technically possible to create a robot with free will, then you will have to say just what kind of mechanism would have to be installed in the robot's brain, or what it already has in its brain, in order to give it exactly the same kind of free will that human beings have, or appear to have.
If you do not accept that it is technically possible to create a robot with free will, then you will have to say just what kind of mechanism you think human beings have that gives them free will. (If you want to talk about why a robot cannot have this mechanism, you will have to do more than just say "machines can't do this." You will have to say what this mechanism is, and why something that a human brain does using neurons and synapses cannot be done with some mechanism that does the same things as neurons and synapses.)