Correct time online?

How to enter that code on Windows? I have installed exiftool and I have tried enter that code on cmd and warning “exiftool is not recognized as an internal or external command…” appear. I tried to run exiftool.exe, it is only show the information text and cant enter command. Please help, I dont have proramming backround and I cant find easy-to-understand tutorial on Google, and I really need change my photos date and time for upload on mapillary