I have tried to apply solutions from other topics related to issues with content script but they doesn't worked. Source in dev tools doesn't see content script from that extension. I recive an error from console of extension
Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.
Looks like extension doesn't see content.js at all.
So, I my case - content.js doesn't respont and work. Did I missed something in manifest.json?
manifest.json
    "name": "Notification Extension",
    "version": "1.0",
    "description": "Build an Extension!",
    "permissions": [
        "storage",
        "notifications",
        "alarms",
        "activeTab",
        "tabs",
        "http://*/*",
        "https://*/*"
    ],
    "background": {
      "scripts": ["background.js"],
      "persistent": false
    },
    "browser_action": {
      "default_popup": "popup.html"
    },
    "content_scripts": [
      {
        "matches": [
          "http://*/*",
          "https://*/*"
        ],
        "js": ["content.js"],
        "run_at": "document_end"
      }
    ],
    "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
    "manifest_version": 2
  }
content.js
console.log('content.js is working');
chrome.runtime.onMessage.addListener(
    (request, sender, sendResponse) => {
        if(request.createAlarm){
            console.log('alarm senedet to content.js')
        }
    }
)
popup.js
chrome.tabs.query({active:true, currentWindow:true}, (tabs) => {
    chrome.tabs.sendMessage(tabs[0].id, {createAlarm: true, message: 'sending to extension'}, (response) => {
        console.log('message arrived');
    })
})
Thanks for your help!
 
     
    