A logo and a favicon are 2 of the most common things people reach for a plugin to handle. In Loupely Canvas you do not need one. WordPress stores both, and the theme gives you a single place to set them and a token to place the logo.
Set them from Site basics
Go to Appearance, Loupely Canvas and open the Site basics section at the top. It shows whether a logo and favicon are set, with a button straight to each control. You can also reach both under Appearance, Customize, Site Identity. WordPress keeps them in sync either way.
The favicon needs no code
The favicon is the small icon in the browser tab. Set the image under Site Identity and WordPress prints the right icon tags into every page automatically. There is nothing to place and nothing to write; setting the image finishes the job.
Place the logo with a token
The logo is set the same way, but you decide where it goes by dropping the {logo} token into your header or footer markup:
<a class="brand" href="{home_url}">{logo}</a>
Canvas renders the logo as a linked image with the class custom-logo, which you size with your own CSS in the Head code box. With no logo set, the token renders nothing, so the markup stays clean until you add one. For the other header and footer tokens, see using tokens in the header and footer.