Shared hosting owner may try to contact hosting provider, but providers may not enable allow_url_fopen

Server can open "/usr/local/lib/php.ini" (if its empty then he have to find file in different location)

Modify following lines and insert them at the bottom of the opened php.ini file:

[PATH=/home/myusername/public_html]
allow_url_fopen=on
PATH is the path to the script that requires allow_url_fopen, sometimes it is needed to use root directory of the content management system

Save file, no need to restart anything, just reload page in web browser by Ctrl+F5