Battery health

Start here: https://www.apple.com/batteries/maximizing-performance/. You can charge your phone overnight with no problem. In fact, if you have it charge overnight, you can do an automatic iCloud backup every night.

Batteries charge until at capacity, and then charging stops. If still plugged in they run on external power. When unplugged they switch to running off battery power. Putting the phone on the charger every night while you sleep will not hurt the battery, nor does it cause problems if you’re using the phone while it is charging.

Themir wrote:

what’s the best routine of charging

Iphone13 pro?

does charging overnight hurt battery health?

and does working with phone while charging damage battery health?

I'd say charge it the way that works well for you. The replacement cost is such that I generally don't think it's worth worrying about.

Overnight charging isn't a problem. It's a bit complicated, but there are things that Apple does to reduce stresses on the battery. When it's fully charged it will stop charging the battery, while it will also supply power to the device such that the battery isn't needed unless it needs more than the external power source can supply. It's simply not safe to charge a lithium-ion battery continuously when "full" and sophisticated charging systems avoid that.

Using it while charging is pretty normal. Everything is handled in the background. There are all these little things that can theoretically improve battery longevity, but they may not be worth it when all the steps needed are incredibly inconvenient and the replacement cost is relatively low. The way I think of it would be "Does the battery serve you, or do you serve the battery?"

Honestly I'd say that the way to make the internal battery last the longest is to not use the battery as much as possible. That's actually not that hard with a battery case, an external battery pack, or hooked up to power.

See also here:

When to charge your iPhone or iPad - Apple Community