This is the standard verification method.
When setting up with this option you can use the OpenSea collection link, a specific token link from OpenSea, or the contract address in the text box.

Setup for verification

In this example, I'm using a link to a specific NFT within the collection. This is again 1 of 3 methods for verifying. Just paste and Save.
Next you'll select the role you'd like your users to get after verifying. Hit Save.
Once saved you're ready to go. Below is an example flow.