Troubleshooting

I turned on catalog mode but shoppers can still add to cart.

That's how it works today — catalog mode doesn't change the store yet. Hide the products, use Ask for quote pricing, or put the seller on hold.

I can't find where to enter a Buy now link.

There's no screen for it yet.

The Catalog Mode page says the module is not enabled.

Switch on Catalog Store in Settings → Modules.

No sellers are listed.

Choose the All filter; Only catalog-mode shows only sellers already switched on.