Project to make an extension to detect phishing URL

Question

Objective: This project aims to make a chrome extension that can detect any phishing URL whenever a page loads.

Current Processes: I have made an API in which whenever we pass any URL, it will give a response as it is a phishing or not phishing URL. After making the API, I m following the method to make the manifest, HTML, and JavaScript files. API Payload: URL: https://phishingurldetectorapi.herokuapp.com/predict1 (Method = Post)

Body:
{
    "url" : "www.google.com"
}

Response:
"It is  not a phishing url"

I want to pass the URL of any page whenever it loads in the "url" field of my API and it can display the response.

Issues: I am currently stuck in the part on how to pass the URL using javascript in my API body. Can anyone help with this?