Authenticating allows you to change your name and increase the minimum payout as well as updating your difficulty.
Authentication is done via the built-in login link for pools in the chia-blockchain software:
Select the 3 dots at the top right of your PlotNFT and click on "View Pool Login Link":
Then copy the login link by clicking the "Copy" icon at the bottom of the modal:
Finally paste the copied url into your browser and hit enter.
First generate the login link via the
chia plotnft get_login_link --launcher_id <your launcher id here>
Then copy the login link, paste it into your browser and hit enter.