Simple chrome extension to read data using xpath hit api and return response

Extension Type:

Chrome extension (Manifest V3)
Minimalist popup UI (plain HTML/CSS, no heavy frameworks)

Popup UI Features:
3 input fields:
Free text field
XPath of source element (to read text from)
XPath of target element (to update with API response)

Buttons:
Submit → triggers the workflow
Clear → resets all fields

Workflow (on Submit):
Locate element via source XPath → read its text content
Send that text to a REST API endpoint (API WIll be given to you)
Receive API response
Locate element via target XPath → replace its value/innerText with response body
Handle all actions only on button click (no background polling/retries)

Error Handling:
Show simple error message in the popup (if API call or XPath fails)
Avoid console-only logs

Deliverables:
Full, commented source code (manifest, popup, service worker/background, helper scripts)
Unpacked extension folder (ready to load into Chrome)
Short README with local testing instructions
Code comments showing where to insert API URL, headers, auth keys

Acceptance Criteria:
Popup with 3 input fields + Submit & Clear buttons
Correct XPath lookups, API call, and DOM update on Submit
Clean UI & minimalist layout
Graceful error handling