Oh, I just read Google Play store, must be Android then.
in your project folder, go to
you have your debug apk file here, which can work well, but I advice you to follow these guidelines
After that, you can send the generated .apk file by mail (they will just have to click it to install)
If the file is too big, upload it on www.filedropper.com/ (Or the site you prefer)
If you are developping on iOS, this is not possible, and you should bring your mac to install it manually on their devices unless they are Jailbroken. (Works too with Android devices if you can’t to the previous steps)
Just plug their devices on your mac, open xCode project in project_Folder/platforms/ios/, wait for the symbols to be processed, and click run on selected device