If you choose to renew your subscription from our website you will go here and choose the 'renew' option.
You'll be asked to login to your informant sync account first. This will be the same login detail that you have logged into the account in informant application at informant settings>accounts>informant sync on your iOS/Mac/Android devices.
Then add the renewal to your cart and complete the checkout process. The next login you'll be asked to do is for the purchase system. This is not necessarily the same as your informant sync username unless you specifically set it up that way. You will only have a purchase system login if you have previously made a purchase directly from our website.
If you still have trouble, please contact support with a screenshot of where you are getting the error and the informant sync username you are trying to renew.