You can upgrade your subscription plan directly in your account settings. Please do remember that the upgrade is not effective immediately, but on the date of the next subscription renewal.
Please go to your account settings and click on "Subscriptions & Bills".
There click on the green button "Change your Plan". You will be redirected to our subscription page in order to change your plan:
Please choose the plan you will want to start once your current one expires.
Finally, confirm your decision:
Your new subscription plan will now be displayed as "Upcoming plan" in your account settings under "Subscription & Bills":