How do I remove the 2 buttons at the bottom of the sidebar?

Hello!

How do I remove the 2 buttons at the bottom of the sidebar for buy now and Angular 6+ as shown here: https://d.pr/i/OucO6v?

Additionally, can I hide the application behind authentication so not anyone can get to it?

Also, is there a way to update the favicon?

I think I already answered to these questions here Few Questions on email template builder