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:
use the ‘add custom token’ function and enter the token’s contract address;
or simply paste the token contract address into the search bar when viewing the token drop-down menu
If you enter the contract address and the token doesn't show up, please confirm that the 1inch site is switched to the correct network of the token (using the toggle button at the top of the screen).
***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.