I have an IPhone 6 that had died and I accidentally left with battery drained for about 3 days. Now when I proceed to charge I get bootloop

So as I said I left the phone dead for days to the point where it won't even show the dead battery icon. Now when I try to charge it, it shows the apple logo then goes black then repeats the process again. When I unplug it the screen instantly goes black. The phone was working just fine before I let it die. Any help?

Leave it on charge for at least two hours, then press both home and power at the same time.

Hold them in for around 10 second until it goes back to the Apple logo, then release.

It's a routine thing with phones and tablets. If the battery gets so low the device stops working, the content of the RAM gets corrupted - but it "knows" it was not turned off, so tries to continue whatever it was doing when it gets power again - and keeps crashing trying to process garbage.

The two button restart forces it to power up as if it had been shut down, so it clears the RAM first rather than trying to "wake up" and continue things.

It does not delete anything, just does a "cold boot".

[For Android, it's usually power and volume up; for an iphone without a home button (iphone 7 etc), it's power and volume down, I think].