How do you make you batterie heath go up

You can't. You would have to get a new Apple battery to do so. This article may help:

iPhone Battery and Performance - Apple Support

Battery Health will always go down......about 1% on average per month.

Make sure that Optimized Battery Charging is enabled and connect your phone to the power adapter at night and let it charge all night.....every night.

That is the single best thing that you can do to preserve the health of your battery.