Our Community page offers daily links which can grant you a couple of extra Runes.
The links that will reward Runes are usually followed by "Claim & Train" and these links will expire within 24 hours or when it meets the maximum number of claims (usually specified on the post).
Please make sure to use the same device when selecting reward links that you are playing the game on.
When selecting the reward link, it should redirect you to the game.
If you have any issues, you could try to copy the reward link and paste it into a browser instead on the same device.