nextgen plus fb sharing is not working in mobile from lightbox

Hi,

i have been using nextgen plus for sometimes now.everything working perfectly fine. until my client have a need of social sharing in which it is.
i have activate social sharing with light box nextgen pro.
issue is that after all configure in Desktop it sharing button is working fine but when i have used it in mobile problem is there. i have a need to put url link of the post i have to share it myself so i confuse same plugin and same configuration but why in mobile is not working or i misconfigure something pls help

thanks in advance
wasan prakitsuwan
wordpress newbie

https://wordpress.org/plugins/nextgen-gallery/