You can upgrade to Pro in a couple ways:
If you have a Tracks subscription, you currently cannot upgrade to Pro during the same billing cycle. However, you can cancel your account, wait till the renew date and then upgrade to Pro after.
You can also send us a message so we can manually upgrade your account. However, we will divide the remaining time by 2. For example, if you have 20 days left before your renewal date, we will upgrade your account to Pro with 10 days left. After 10 days you will need to renew your account yourself by upgrading again to Pro.
Contact us here if you have any questions about this.