If you want to enable/disable the php functions like allow_url_include and allow_url_fopen, You can simply do it by editing the php configuration file.These functions can be disabled in the php configuration file of some shared hosting server. You can easily manage these function by creating a custom php.ini file under your public_html folder.
Step I : Create/Open php.ini file under the public_html folder of your domain.
Step II : Add the following lines to enable above php functions.
allow_url_fopen = On allow_url_include = On