If some editing features are locked behind a paywall although you have already paid for a subscription to Remini, it's highly possible that your current plan doesn't include the use of customisable tools.
In this case, an upgrade of your subscription is required to customise your enhanced results. Developing new features and taking the app to the next level take up a lot of resources. This is why a higher subscription level is needed to use some of the available options.
To upgrade a plan, simply follow the steps available on the paywall that pops up whenever you try to use a locked feature and start your new experience right away!