How to make the web page cooperate with the ios APP?

That’s it
I already have a webpage
I want to make an ios app to interact with the webpage (including mysql php)
Where should I start learning this?
For example, on ios, as long as some fields
can be input into mysql after being sent
and the content on the web page can be displayed on ios

Reply content:

That’s it
I already have a webpage
I want to make an ios app to interact with the webpage (including mysql php)
Where should I start learning this?
For example, on ios, as long as some fields
can be input into mysql after being sent
and the content on the web page can be displayed on ios