So you want to get App Launchpad setup and running in your lab VCD but find out there is a requirement to have your VCD instance exposed publicly to the internet. For most of us with a home lab or even a lab in the office, this is not possible. Luckily there is a way to make this happen! (This will hopefully be removed as a requirement in the future but as of writing this with ALP 2 it is.)
The problem is step 3 in the process shown below. This is where the Marketplace requests VCD to create a catalog.

So what follows is a walk through of what you can do to circumvent this issue. (Thanks to William Zhou who helped work to put this together.)
Step 1. Get logged into the VMware Marketplace. The link is here. Then browse to On-Prem applications.

Step 2. Multi select several applications that are applicable for both On-Prem and Cloud Director. Click Subscribe to open the subscribing page. Click On-Prem and proceed to create the subscription.

Step 3. On the last screen of subscription creation, click Check Subscription.

Step 4. View the details of one application you just subscribed.

Step 5. Copy the subscription link to clipboard. You’ll need it later so don’t loose it!

Step 6. Go to vCD where you have already installed App Launchpad. Logon to Provider portal. Open Organizations. Then jump to organization App Launchpad.

Step 7. In tab Libraries → Catalogs, create a new catalog.

Step 8. Name the catalog and toggle on Subscribe to external catalog, paste the subscription link from your clipboard.

Step 9. Once the subscription succeeds, the application import starts. You can check progress from vCD task panel.

Step 10. Wait for the application import to complete.

Step 11. Open App Launchpad portal, navigate to Applications tab, you can see those Bitnami applications. Then you can publish this catalog to your tenants and create workloads there.

I hope this helps you to get App Launchpad running in your lab! Happy launching.