Small bright spot inside of my screen

Hello. Hope y'all are in good health.

I noticed a bright spot on the screen. It's always visible, but mostly visible when the screen is displaying lighter colors, especially white. It almost looks like something is pressing the back of the screen. But I have been handling my phone very well since 4 years now. I did look online about this but couldn't find anything relevant.

Can you please let me know what it is and how can it be fixed or any suggestion would be appreciated.