Sign-in to your WordPress admin account from your website or blog.
View the Plugins tab and Click on “Add New.”
Search for the "MailUp" plugin on the search tab
Click on “install now.” and click "yes" to confirm.
Click on "Activate plugin."
Go to the the Appearance section and click on the widgets tab. You can see all the available widgets including the MailUp one.
Drag the MailUp widget into the main sidebar.
You can now go to your website and check that the MailUp newsletter plugin is installed.
Configuring the plugin
Before you can connect your WordPress site to your MailUp account by filling out the fields on the setup page, you will need to activate the MailUp API in your MailUp account: