go to Settings, scroll down to Security, and select Unknown sources. Selecting this option will allow you to install apps outside of the Google Play store.
"https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwji0cT8oov5AhUgs4QIHe1DDeQQFnoECAQQAw&url=https%3A%2F%2Fwww.cnet.com%2Ftech%2Fmobile%2Fhow-to-install-apps-outside-of-google-play%2F%23%3A~%3Atext%3DSetting%2520up%2520your%2520device%2Cof%2520the%2520Google%2520Play%2520store.&usg=AOvVaw1WE2IvvDmKKmdgp3klFkd-"
