We do not have a "contract address".
RDD is not an ethereum (ERC) token, and requires a wallet supporting RDD's native blockchain, such as Guarda, Coinomi, or the Redd Core Android or desktop Core wallets. Only the Desktop Core wallet allows you to stake and secure the RDD network at this time, also known as "staking rewards".
Those ReddHeads who do stake on the Core wallet receive a dynamic annual reward between 5-25%, currently (Aug 2021) at ~10% annual return. Simply for holding RDD in our wallet and securing and validating the network automatically!