Once you have completed the units and feel comfortable with the material, take the certification exam. You must register for the exam - it can take up to 24 hours for the exam to be ready. The exam lasts for approximately 180 minutes. There are no pauses. There is a $10 fee for the exam. 

Register for the exam here - https://www.webassessor.com/form/ssoLogin.do?method=process&provider=google&brand=GOOGLE&forcesubmit=false Links to an external site. 

Certification FAQ page - https://teachercenter.withgoogle.com/certification_faq Links to an external site.

When finished, take a screenshot, that includes the date and time, and upload your results. Note, you still receive credit even if you do not pass the exam.