facebook sharing problem

Hi community,

I have a question regarding facebook sharing.

I want to share my website page which was already login. This page has layout name channel layout.

so when i am trying to share my page…facebook could not reach my meta tags because , it is redirecting to login page. login page has different layout called home layout.

so my question is,

how to update meta tags which is located in main layout.

layout files are

main.php - common code --> meta tag is here

channel.php - specific to channel

home.php - specific to login