Document Credit Limits
Each time you "Create a New Document" by entering your target search query and creating a doc, 1 document credit will be used.
For those using the Basic plan, those credits will reset back to a new slate of credits (0 credits used) on the 1st of every month (12 AM UTC time). For the Basic plan, you can see the number of document credits used up to 30 in the Account --> Subscription page. This is not relevant for the Team plan because there are unlimited document credits.
You can see how many document credits you've used for the month in the Account --> Subscription page (screenshot below).
In addition and not limited to Frase's right-side panel, each "document credit" consists of 4 total editor tabs, two initially appearing, named "Content Brief" (tab for outline) and "My Content" (main tab for writing the finished product). The option to add another tab exists by pressing the "+" icon next to the My Content tab.