Ensure that you are logged into the app and can see the main dashboard.
Click the settings icon at the top right hand corner of the window to go to the settings pages.
Click the 'Integrations' button on the left hand side accordian to expand the integrations panel.
Select the 'Store Setup' option in the panel that opens.
Click the 'Connect Store Or Marketplace' button near the top right hand corner of the screen.
In the dialog that opens, select the logo of the store that you want to connect and a form should open.
In the form, enter the correct information and proceed by clicking the 'Connect' button at the bottom of the form.