There is no "repair" of the screen, rather it has to be replaced, if it is malfunctioning. If the computer is less than one year old, then the repair may be covered under your warranty unless the screen was damaged through user negligence (as stated in the warranty.)
If the problem is software related, then backup the drive, erase the drive, and reinstall macOS. Test to see if the problem is solved. If it is not, then the screen is damaged.
Make an appointment at the Apple Genius Bar for service after the stores re-open. If you need to find an Apple Store - Find a Store - Apple. Also, see How to find your nearest Apple Authorized Service Provider (AASP) or Distributor (AAD). You may also get Apple authorized service at a local Best Buy or contact Apple for further options.
Contacting Apple Customer and Support Service
- Apple Store Customer Service at 1-800-676-2775 or visit online Help for more information.
- Primary support help at Contact Support.
- To contact product and tech support: Contacting Apple for support and service including international calling numbers.
"Your Apple-branded or Beats-branded hardware product (“Product”) is warranted against defects in materials and workmanship for a period of ONE (1) YEAR from the date of original retail purchase (“Warranty Period”) when used in accordance with Apple`s user manuals (refer to www.apple.com/support/country). Under this warranty, you will be able to direct your claims to Apple even in situations where you purchased the Apple Product from a third party.” [Apple One (1) Year Limited Warranty – Accessory - For Apple and Beats Branded Products Only.] You get 90 days of free telephone support from date of purchase of your Apple device. You should use it.