Honestly, I don't know, because I have not used the GNS3 setup described at https://github.com/extremenetworks/Virtual_EXOS/blob/master/GNS3_EXOS-VM_Guide.md
myself. I have always used GNS3 installed on my GNU/Linux system using the distribution packages.
Anyway, the image at the bottom of the GNS_EXOS-VM_Guide.md shows that a GNS3 appliance is started and shows the IP of that appliance. Perhaps the settings of the locally running GNS3 program and the virtual appliance do not match. You might find a setting in the GNS3 running on the local machine to which GNS3 appliance to connect. There you need to enter the IP shown in the GNS3 appliance window.
Hope to help,