If the FlexDeploy download link and bootstrap code are not present in the newly created assessment, there was probably an issue with provisioning the subscription. If you PM me I can take a look at your licensing, but this will most likely need to be resolved by opening a ticket with Flexera support.
Unfortunately there is no way to revisit the option of selecting "Yes" or "No" to using a FlexDeploy during the configuration of the RN150. The FlexDeploy needs to be deployed and configured prior to this step in the RN150 configuration so that you can select the "Yes" option and specify the FDP's IP address. You will need to download and re-deploy the RN150 in order to get it configured for an on-Premise deployment.