If you cannot find a token by its ticker in the drop down menu, it means the token is not whitelisted on 1inch.
To be able to trade a token that’s not whitelisted, you have two options:
you can utilize the ‘add custom token’ function and enter the token’s contract address;
Please, be aware that by adding a token as a custom token, you confirm that all further interactions with it are at your own risk.
you can apply for whitelisting of a specific token, especially if you are involved in a project whose token you would like to add. See the whitelisting requirements here.