The Power Apps Patch function can be used to create or update data, including SharePoint lists.
Power Apps Patch function
For example, you can use the Power Apps Patch function to create a SharePoint list item. Or you could use Patch to update a record in SQL server.

This is quite easy and well documented on the Power Apps Patch function page.
When you look at using Patch to update an item, you might also want to consider using Update or UpdateIf.
Create an item with the Patch function
But what do you do if you now want to get the details of the item that you just created. It would be helpful if you could collect the data created without having to query your data source.
Today I discovered that the Power Apps Patch function returns the item created. So that means that I can set a variable.

This variable can then be used to get the ID of the list item.

Hi Pieter Veenstra,
Based on your many experiences using Sharepoint List/ Flow,
What would be less error-prone to create some Items from Powerapps , Patch directly or via Flow create item/ Send HTTP request? Because sometimes Patch 10 items at the same time takes very long time for user on mobile connection
Interesting question. I might create a post on that soon.
First of all when you use the patch you should use it in combination with a Set so that you collect the result. This may help with error handling in Power Apps.
Thee isn’t a straight forward answer to the question if Flow or Power Apps is better at updating data. Flows happen in the back ground unless you collect a result back. So that might be good, however when flows update the data you will find yourself refreshing data in your PowerApps more often.
Further to my previous comment. You might also want to look at UpdateIf. It is faster than Patch.