If you are using the Picture Window template, your blog does not automatically display an image header, even if you upload one to the Header section. You must edit the blog HTML to add your own ...

Locate your header image on your desktop and wait while Blogger uploads the header to your blog. Select the placement option "Instead of title and description" and click "Save." ...

Open the form you want to edit in Microsoft Forms; Click the form header; Select Insert Image (picture icon) Search for images on Image Search, OneDrive, or upload images from your computer.