Depositing ALEX resulted in failed transaction with ERR 3502

ERR 3502 in the contract says unknown token. Perhaps not yet implemented?

Can you pls provide the screenshot of the issues reported?
Thanks for the feedback.

Here is the link to the transaction: Function call (Failed) - Stacks Explorer by Hiro

And a screenshot of the err in result of the contract call:

Screenshot of the explanation of that ERR code in the contract (for convenience):