Select Render Walk → List Tours from the side menu and click the Edit button on the desired tour.

List Tours - click Edit button on desired tour

Go to tab Content / Logo.

Tour settings - Content / Logo tab

Upload the image of the logo and you can optionally choose to add a hyperlink to it.

Upload logo image and optionally add a hyperlink

Click Save on top of the page.

You can adjust the size and position of the logo inside the Editor UI.

Select Render Walk → Editor UI from the side menu. Click on the Logo box.

Editor UI - click Logo box to adjust size and position

Click Save on top right corner of the page.