with below tutorial you can add GMP or any module requested with your script, Please follow:
once you delivered host from hostsale, please login to Cpanel (you can login with user/pass or through client area in hostsale.net website)
then follow below step:
then you should open "Select PHP Version" under software menu, screenshot:
then you should open menu like below screenshot and choose 5.6 r any version php you need, then default GMP will enable, then also you can choose any module more you need:
then you should open menu like below screenshot and choose 5.6 r any version php you need, then default GMP will enable, then also you can choose any module more you need: