Here are the steps you need to follow to switch from a monthly plan to an annual plan:
Step 1. Access your Subscription page
Step 2. On your Subscription page, you’ll have to select the option "Yes / Show annual plans"
Step 3. Now you’re going to see this page showing all the annual plans
You can switch from a monthly plan to an annual plan by clicking on the “Change plan” button
Final Step. After clicking on “Change Plan” you’re going to see a message saying:
“Are you sure you want to change your plan?”
Click on the “Yes, change it!” button to conclude.