First of all, make sure you added your logo at the top of your website page , in the General information section. On the right of your restaurant's name, click Edit, change the logo, and save.
Then, in order to display your logo instead of the name of your restaurant on your Zenchef website, go to Settings on the top right of your Zenchef dashboard.
In the navigation bar, click Website.
Scroll down, and click Yes by Use my logo instead of the title to enable the feature.
Make sure to save the change by clicking Save at the bottom of the page.