itch.io

go to the files app then APK (idk if its APK on samsung because im using oneplus phones) but if you find the file there then you just have to press on it then install but if its maybe a ZIP folder then you should extract it to the download folder and then install the way i said earlier. 

hope this helps but if it dont then just know that i dont use samsung :/

Go to your file explorer (If you cannot find it, install zarchive form the playstore) > go to downloads. you will see the file. Click on it and install.