Note: There are no codes currently available on this page. If you have a code that works, post it below, or in a comment.
Promotion codes are typically given on the official Lords Mobile IGG forums:
You can claim them in the link below. The first box is for your IGG ID # and the second is for the Promotion Code. It works only once per code per IGG ID.
You can find your IGG ID by going into settings and then account.