There is no way to access links through keyboard (or through accessibility interfaces). For example tabbing through links in them and activating a link by enter key. There isn't even any API to get link regions out so one cannot do custom handling for them either.

import QtQuick
import QtQuick.Controls
ApplicationWindow {
    width: 1500
    height: 1500
    visible: true
    Text {
        text: "foo <a href=\"bar\">bar</a>"
        onLinkActivated: console.log("link activated")
    }
}