Connect your Wallet first.
To swap Erc20 Nemesis Tokens on Ethereum Chain select your Token in the list (Token to Sell) then place the contract in the Select Token field (Token to Buy - NMS Nemesis Erc20 by default).

1- NMS Nemesis (Erc20): 0x77252494c25444f8598a0c74ffc90adc535291a9