Dear Lim Choon,

It means that you may send reiki and/or any healing energies to mother earth.
In reikipath, attunements are given freely by moderators and this condition is for an energy exchange which must be done.

I don't know which energies you are using but as I see you're on third level of Reiki.
After when you receive your each attunement here, you may send reiki to mother earth.
And this will provide an energy exchange for the attunement you received.

If you have any questions, please don't hesitate to ask.

Blessings..
Baris