How do I add or import a custom token using its contract address?

To add a custom token, open STON.fi and go to the token selector in the Swap interface. Use the search field and paste the token’s smart-contract address. The platform will automatically detect the token’s name, symbol, and decimals if the contract is valid. After that, simply confirm the import, and the token will appear in your list. This lets you swap tokens that aren’t shown by default or are newly deployed. Make sure you use the correct contract address to avoid interacting with fake tokens. Once imported, the token stays available in your interface until you clear your browser data.

See the link for more details.