SPFx solution using PnPjs with invalid request url

[junnureddy]

I have created an SPFx solution using PnPjs to get List titles in SharePoint, but when I add the web part on the page, list names are not populating in the dropdown and getting the below error.

When I verify developers tools in the browser the request URL has the extra text "_layouts/15". Do you have any idea why it was coming like this?

Request URL: https://xxxxxx.sharepoint.com/sites/WAP7/_layouts/15/_api/web/lists?$select=Title