If you are looking to access all premium features of the app, but it is restricted under the in-app purchase and you want to use it for free, then read the whole article to save your money. https://gettechskill.com/installing-iapcrazy-on-ios/
Install IAPFree: Cydia tweaks are used to bypass the in-app purchase page. In-App Purchases (IAP) IAPFree is one of the most suggested Cydia tweaks for this purpose. https://gettechskill.com/installing-iapfree-on-ios/