Is the sun portal in minecraft real?

No, not in vanilla minecraft. You'd need a mod on PC for that to even exist.

Yes it is and heres how you make it. First kill the wither 90 times as you will need 90 nether stars. Then, craft these into sun god blocks with esth requiring 9 nether stars. Place it as you would a nether portal but flat instead of up. Finally summon a wither in the midle and kill it. Your sun portal is now complete. Beware that you can only use it at night and failure to return before dawn can result in your game glitching. Also note you can only do this in survival. If you summon/kill the original 90 withers in creative it will not work.

Not at all its a mod