The Outlook Extension inside of Outlook must be open while you are composing and sending your emails in New Outlook. I recommend using the pin function to keep the extension open while you are sending emails. You must check the checkbox each time you send from Outlook. There is an option to automatically check the box on your behalf each time you send an email, which makes it more convenient, however, it is somewhat of a burden to use this extension in New Outlook. There is also a setting which you must enable inside the Outlook Extension, called "Create New Contacts"
The Outlook Extension inside of Outlook must be open while you are composing and sending your emails in New Outlook. I recommend using the pin function to keep the extension open while you are sending emails. You must check the checkbox each time you send from Outlook. There is an option to automatically check the box on your behalf each time you send an email, which makes it more convenient, however, it is somewhat of a burden to use this extension in New Outlook. There is also a setting which you must enable inside the Outlook Extension, called "Create New Contacts"