Natty Gamedevs Ai isn't working

When I was following Natty GameDevs tutorial I was using the Nav mesh AI on my agent I am new to AI and how no idea about how to do anything with it. anyway after following the first tutorial and testing my AI nothing happens at all and I did everything he did in the tutorial and everyone in the comments seem to have the same problem but there has been no one who has found the solution can anyone watch the tutorials and find out what is wrong?