In order to pay for the costs for listing a new token, you need to have 10 OWL available at your disposal. There are two ways to obtain OWL:
a. Get OWL using Mesa, the first dapp built on Gnosis Protocol.
Make sure you have have some ETH available for gas fees. If you're using the Gnosis Safe, you can also pay gas fees using other tokens.
Lastly, have the token address of the token you would like to list readily available. Make sure the token you'd like to list is compliant with the ERC-20 token standard, as this compliance will not be checked on smart contract level.