How can i clean my iPhone 7 plus`s camera lens ?

Hello,

iPhone X, iPhone 8, iPhone 8 Plus, iPhone 7, iPhone 7 Plus

Clean your iPhone immediately if it comes in contact with anything that might cause stains or other damage—for example, dirt or sand, ink, makeup, soap, detergent, acids or acidic foods, or lotions. Follow these guidelines:

• Unplug all cables and turn off your iPhone.
• Use a soft, lint-free cloth—for example, a lens cloth.
• Avoid getting moisture in openings.
• Don’t use cleaning products or compressed air.

Your iPhone has a fingerprint-resistant oleophobic—oil repellent—coating. On iPhone X, iPhone 8, and iPhone 8 Plus, the coating is on the front and back. This coating wears over time with normal use. Cleaning products and abrasive materials will further diminish the coating and might scratch your iPhone.

From:

Cleaning your iPhone - Apple Support