The Finish setting up card sits at the top of the Dashboard and tracks five steps. It is not decoration. Each step is checked against the real state of your store, so a step ticks itself the moment the underlying condition is true, and it will not tick simply because you visited the page.
This article covers what each step does and, more importantly, precisely what makes it count as done. If your checklist looks stuck, the answer is almost certainly in the section on step 3.

Choose your Amazon region (North America, Europe or Far East) and authorise the app in Seller Central. On return, the app discovers which marketplaces your account may sell in.
Marked done when: at least one Amazon account is connected.
This is the only step that is a genuine prerequisite for the others. Without it, price sync has nothing to read, Product Sync has nowhere to publish, and Sync now stays disabled.
Full detail: Connecting Amazon Seller Central.
The app scans your store for other Amazon apps, because two apps writing to the same listings will make price and stock flap back and forth. If one is found, you tick which of the four functions it handles, disable them in that app, then recheck.
Marked done when: you have acknowledged the check. That means either the check found nothing, or you worked through the modal and confirmed. It is a warning rather than a hard block, so you can override a persistent detection and continue.
Full detail: Check for conflicting apps.
This is where you tell the app which Amazon marketplace is your default (home) marketplace, and, on paid plans, map individual Shopify markets to specific Amazon marketplaces. The home marketplace drives automated price sync and the home price, and it is what the storefront blocks fall back to. You set all of this on the Markets tab in Settings.
Marked done when: a market mapping is explicitly saved.
That sentence is the single most important line on this page, so read it again carefully.
When you connect an Amazon account, the app already knows your authorised marketplaces, and it can infer a sensible default from them. So the Markets tab may already look correct: your home marketplace is showing, and it is the one you would have picked anyway.
An inferred default does not complete the step. The checklist is looking for a mapping you actually saved, not one the app worked out on your behalf. Until you open Settings, go to the Markets tab, and save, step 3 stays open, and so the checklist never reaches "You're all set".
This is by far the most common reason merchants think the setup guide is broken.
The fix takes about ten seconds.
Step 3 will now tick.

Note
Per-market overrides are plan-limited. Free gets none, so on Free you set the default marketplace only and that is all you need to save. Growth allows 3 overrides, Growth + Markets 10, and Full effectively unlimited.
Full detail: Market mappings.
Link Shopify variants to Amazon ASINs on the Product Mapping screen, so the app can pull live Amazon prices and Buy Box status back into your store. You can use Auto-match one-to-one, which matches by barcode only, or map products by hand using the Map modal, which searches Amazon by barcode, ASIN or product name.
Marked done when: at least one product is mapped. One is enough. You do not have to finish your whole catalogue to clear the step.
Full detail: Product Mapping.
Use Product Sync to publish Shopify products as real Amazon listings. Before anything can be pushed you need to select your target marketplaces, set an Amazon product type for the product's Shopify category, and make sure the product's Shopify Brand (vendor) and Description are filled in.
Marked done when: at least one product is listed on Amazon.
Product Sync requires a paid plan. If you are on Free, this step will not complete, and that is expected rather than a fault. Price sync, the Buy on Amazon button and Fulfilment by Amazon all work on Free without it.
Full detail: Product Sync.
When all five steps are complete, the card changes to say You're all set and offers Hide setup guide.
Hiding the guide only removes the card from the Dashboard so you get your screen back. It does not switch anything off, and it does not undo any step. The space is then given over to the At a glance tiles, the Sync health card, and the two run cards showing your last manual sync and last automated sync.
Tip
If you are on the Free plan and step 5 will never complete, you can still work normally. The card simply stays visible with four of five steps ticked. Upgrade when Product Sync becomes worth it to you, and the last step will tick on your first successful listing.
More help: Troubleshooting.