spfx-angular-elements project working correctly on workbench but not working on sharepoint page

I have created a demo with reference to the below link,

https://gonadn.medium.com/spfx-with-angular-element-crud-operations-using-pnpjs-5a8a18ed6e43

It is working correctly in the workbench. Kindly refer to the below image,

It is not working correctly on the SharePoint page.

Throwing below error in SharePoint list api call

GET https://xyzsharepoint.sharepoint.com/sites/devsite/SitePages/_api/web/lists/getByTitle('TestList')/items?$top=2000 404

Kindly refer to the below image,

Can you please assist me with the same?

Thanks :)