13 PRO MAX SCREEN FLICKERING

Last Sunday morning, I discovered that my phone started screen flickering. Initially, it was only on half of the screen, but now the entire screen is flashing white, rendering it unusable. What should I do? Although I contacted APPLE SUPPORT, I didn't receive any assistance. Can I get free repair service? My phone has never been dropped on the ground or submerged in water. However, my warranty has expired.