Click Create New Master Keyword and add your keyword in the master keyword field.
Click Add Keyword.
Set the Validity of the service, if you do not have an end date in mind please chose a date far in the future.
Click Next.
Setup a Reply message, if you require one. This will automatically be sent as a reply to any inbound messages received and will be chargeable at your agreed price.
Check the details on the Summary page, Confirm and Complete.