Need help with a chrome extension I'm building

You need to add something like this to your manifest.json file:
"content_security_policy": "script-src 'self' https://fonts.googleapis.com/css 'unsafe-eval'; object-src 'self'"

Not sure about the exact one for blob, but I hope that gives you a hint.
Example from my code:
manifest.json
{
"name": "",
"version": "1",
"description": "",
"manifest_version": 2,
"permissions": ["activeTab", "webNavigation", "storage", "tabs"],

"icons": {
"128": "assets/icon_128.png",
"48": "assets/icon_48.png",
"16": "assets/icon_16.png"
},

"background": {
"scripts": [ "background.js","runtime.js", "scripts/jquery-3.4.1.min.js"],
"persistent": true
},

"content_scripts": [

],

"browser_action": {
"default_icon": "assets/icon_16.png",
"default_popup": "index.html"
},

"content_security_policy": "script-src 'self' https://fonts.googleapis.com/css 'unsafe-eval'; object-src 'self'"
}

As mentioned before, it would be good to see the code.

I am probably not the best person to help, since I created my first extension this week (waiting for the review from Chrome/Firefox store), but maybe this will help.

My extension:

• I have a (1) popup.html and a (2) popup.js.
• When the user clicks on my extension icon, the (1) popup.html is displayed.
• Inside the (1) popup.html, I have a button "Activate Extension". When the user hits the button, I do something with all the input fields on the current page:

So, on my (2) popup.js:

// A) Add a listener to my button.
document.getElementById("activateExtension")  .addEventListener("click", async () => {
const currentBtn = document.getElementById("activateExtension");

// B) I get the current tab information.
let [tab] = await chrome.tabs.query({ active: true, currentWindow: true });

// C) I run the code inside my "getFormFields" function on the current tab.
chrome.scripting.executeScript({
  target: { tabId: tab.id },
  function: getFormFields,
});
});

On the same (2) popup.js file, I have that function ("getFormFields"):

function getFormFields() {
let inputs;

 // D) Reference to all the "input" tags on the current tab.
inputs = document.getElementsByTagName("input");

// DO SOMETHING HERE...
}

People would need to look at code in order to solve a dev bug. One common reason for this error is when you try to run inline javascript instead of including it via file, as it is mentioned in the error.
So make sure you js is extracted to an external file and included in html file via script tags.