$TKMN is available on Uniswap and Bilaxy as Eth swapping pairs. The amount of $TKMN held in your wallet controls the amount of features available to the user.
You can buy $TKMN from Uniswap here.
Logging in requires that you sign a signature with your metamask wallet. The metamask wallet implements the EIP712 standard to ensure security usability. Note: at no point is your private seed revealed. Once the wallet is signed, this is the wallet attached to your account and we use it t check that you have sufficient $TKMN tokens.
If you are uncertain about what your metamask is asking a signature for, you can inspect the request in your metamask and see that it is only a timestamp value.