To manually convert a Contact to a Member, open the Contact's profile and select the Action drop-down button at the top.
Next, select Make Website Member on the drop-down menu shown below.
📌 Important: The best way for a Contact to become a Member, is for them to go through your checkout process or to sign up for your course or membership through a checkout page. For this to work, you need to have a Member Group linked to your Store products and your Store products need to be linked to your checkout page/s.
On the next pop-up screen, select the correct Member Group/s and hit Confirm.