To import a classroom you have already created in Google Classroom to GoGuardian, start with the "Add Classroom" button in the top right corner of your dashboard main view.
Scroll to the bottom of the window that pops up and choose "Add From Google."
If prompted, enter your Google account credentials. Then, select the classroom you want to import.
Your classroom will be imported, and your student list will automatically sync. Updates to your student list will be synced every hour; to manually force these changes to happen sooner, click the "Sync Students from Google" button.
Once imported, your classroom will appear on the main page of your GoGuardian for Teachers dashboard, with a "G" logo in the bottom right-hand corner, to indicate it is a Google Classroom.