Problem with settings

Hey there

I have a problem with my settings on ionic 5. I started to develop my app since two weeks.
Before to start I totally forgot to add cordova. So I did it yerstaday and I can see this error:

On my IDE I have three errors on config.xml

This the error on the ide : URI is not registered (Settings | Languages & Frameworks | Schemas and DTDs)

When I run my app Ionic cordova webbrowser It works.

But I have an error on the webbrowser:

Do you have an idea of this problem ?

Thank you for your help,

Do you install Android studio?

Yes I did and I updated too, same error

Can you explain exactly why you need Cordova in the first place?

Beacause I have some a problem in my webbrowser and I need to use the vibration.

Capacitor Haptics.