I uploaded PHP files into Online File Manager but when I open my domain I can't see them. From my hosting provider I have message :"Congratulations! Your free hosting account has been activated. You can now use FTP or the file manager in your cPanel to upload your site."
My files are uploaded in htdocs folder.
What can be a problem?
If I am right, you have uploaded PHP file in that folder. If you are using hostinger like free server, there will be public_html folder where you should upload.
Another, check if you have index.html or index.php if not then upload any dummy file with index as name check if dummy file is coming on opening website