Once you've assigned tracks and added your works information to your contract, you'll need to send it from the contract screen.
You can reach that either from track level here:
Or by navigating to the licensor via the Accounting section and finding the contract under their Contracts tab:
Select "Save & Email Licensor" to save and send the contract.
They will receive a notification by email, which a link to their licensor area through which they can view and sign.