Unchecked runtime.lastError: Could not load file [chrome extension]

Question

So I'm creating a chrome extension using manifest version 3. Since it is prohibited to load external sources I've copied the html2canvas.min.js into a local copy in a folder named libs.

I need this library in a content script, named get-div-image.js, since it is necessary to access the DOM. This content script is then fired from a popup.js along side my declared html2canvas.js like so:

chrome.scripting.executeScript({
  target: {
    tabId: currentTab.id
  },
  files: ['html2canvas.js']
}, () => {
  console.log('html2canvas injected');
  chrome.scripting.executeScript({
    target: {
      tabId: currentTab.id
    },
    files: ['get-div-image.js']
  }, () => console.log('Content script injected and executed.'));
});

my manifest.json looks like this:

{
    "manifest_version": 3,
    "name": "Images Grabber v2",
    "version": "1.0",
    "description": "Monitors the screen and takes screenshots.",
    "permissions": ["activeTab", "storage", "tabs", "background", "scripting"],
    "content_security_policy": {
        "extension_pages": "script-src 'self'; object-src 'self';"
    },
    "background": {
      "service_worker": "background.js"
    },
    "action": {
      "default_popup": "popup.html"
    },
    "host_permissions": ["<all_urls>"],
    "content_scripts": [
        {
            "matches": ["<all_urls>"],
            "js": ["contents/get-data-urls.js", "libs/html2canvas.js", "contents/get-div-image.js"]
        }
    ],
    "icons": {
      "128": "icons/icon.png"
    }
  }

and my folder structure is the following:

extension/
│
├── manifest.json
│
├── contents/
│   ├── get-data-urls.js
│   └── get-div-image.js
│
└── libs/
    └── html2canvas.js
...

But when the extension is fired, I get this 2 errors:

Unchecked runtime.lastError: Could not load file: 'html2canvas.js'.
Unchecked runtime.lastError: Could not load file: 'get-div-image.js'.

What am I doing wrong?

EDIT Changing

files: ['html2canvas.js'] to files: ['libs/html2canvas.js']

and

files: ['get-div-image.js'] to files: ['contents/get-div-image.js']

seems to have suppressed the error, but the script doesnt seems to be injected? And also this notations is not consistent, since I have declared above files: ['get-data-urls.js'] and It works just fine