Can I get battery replacement at 88%. Battery health

Apple won't likely replace the battery until its health has dipped to 80% or less. You can ask, but they will likely say no.

Yes, you may have to pay for it.

SravanKrA wrote:

Yes, you may have to pay for it.

We can't say yes, for sure. I had a friend take their phone to the Genius Bar for a battery replacement at about the same health level and Apple said they needed to wait for the health to dip to 80%.

You’re roughly two-thirds of the way through that battery estimate, with a third of the estimate remaining.

And there’s no predicting how long that remaining third of that estimate might last.

All batteries inevitably and inexorably degrade, but not at any rate easily predicted.

You probably didn’t buy this iPhone solely to monitor a battery capacity estimate too, so you’ll want to continue to use your phone until it needs additional charging cycles for what had been your normal daily usage, and then evaluate battery replacement or phone replacement.