You can customize the login page by adding a logo or a background image of your choice. You need to be an administrator to perform this task.
You can upload the following formats as account logo or background image:
Go to Settings > Account > Look & feel.
To change the background image:
Hover your mouse over the image under Set background image for your account login page.
Click the plus icon and upload the new image.
The background image should have at least a width of 1280px and a height of 720px.
To change the existing account logo or the account login logo, hover your mouse over the image under Set account logo and Set account login logo. Click the plus icon and upload the new image.
The logo should have at least a width of 200px and a height of 80px.
Save your changes.