allow_url_fopen, How to Enable
This can be done via your php.ini file by adding the following line:
allow_url_fopen = On
The php.ini file is where you declare changes to your PHP settings. You can edit the existing php.ini, or create a new text file in any subdirectory and name it php.ini.
Refer to this link to start with the text file: What is php.ini?
You can read more about php.ini by clicking the Related Articles.