You can follow these steps to change Logo on Ghost Blog (All Pages or One Page).
#Option 1. Change Logo on All Pages
#1. Click Gear icon at the bottom left
#2. Search the keyword Design or click Design & branding
#3. Click Customize
#4. Click Upload logo
#5. Select the logo and click Open
#6. Click Save
#Option 2. Change Logo on One Page
To change Logo on One Page, you can use this code to Code Injection > Page Header. You can change Pixabay in the code to desired logo url.
<style>
header#gh-navigation img {
content: url(https://cdn.pixabay.com/photo/2024/12/20/11/53/architect-9280053_1280.jpg);
}
</style>
Result
