The current supply of DESO is best viewed on the reference DeSo node here. There are other sources, but this endpoint hits a fully-synced DeSo node, which runs through all of the actual token balances on-chain to compute a value that is up-to-date down to the second.
Due to burn from transactions and APY paid to staking, the value changes over time, and Coinmarketcap and Coingecko are not dynamically-updated at the time of this writing, so it's best to check the nodes themselves as the source of truth.