Merchant login to Merchant page dashboard, to be able to modify merchant's settings that consists Profile, Credentials, Report, and Developer settings.
Click Settings on the left menu of the dashboard and it should show sub-menus as shown below.
(Settings menu)
Profile Menu
A page where merchant can change their business's logo by their liking so their logo can be displayed on merchant's payment landing, billing, and email notification.
Merchant needs to click choose file to upload their logo with the format: