To import the Amazon products to Magento 2,

• Go to the Magento Admin Panel.
• In the left navigation bar, click on Amazon Product Importer.

• Now click on Selective Products Import. You will be navigated to the page as shown below:

• Now from this page, you may easily import the products.
• Select the product(s) and click on the Actions bar on the left side, above the product list. From the drop down menu, click on Import, as shown in the figure.

• Click OK when the box appears, asking you to confirm your action.

• Your product gets imported and the message appears.

For CSV Import,

• Click on the CSV Import button on this same page and the CSV file will be uploaded and listed.
• Now just select it and select Import from the Actions bar like done earlier.
• Your product will be imported.

Product Import by Uploaded CSV,

In case you want to import the products through the Uploaded CSV that you uploaded in the configuration process,

• Click on the Product Import By Uploaded CSV on the top right of the page, next to the CSV Import button.
• Your product will not only be listed, but will be imported successfully.