If you have enabled family sharing for subscriptions, in your Apple account settings, then your family members should immediately get access to Kiddopia subscription without the need for a Kiddopia account.
Please follow the below steps to turn ON Family Sharing -
Go to Settings > [your name] > Subscriptions.
Tap on a subscription, then turn Share with Family ON.
Alternatively, you can also share your subscription using the Sign-in feature of the app.
To share your subscription on another device, please follow these steps:
Open Kiddopia on the device that you used to purchase it.
Tap on the Settings icon.
Then, tap on Sign In and follow the instructions (The app will ask you to use your Email/Mobile).
Once you have signed in, please follow these steps on all the devices on which you wish to share the app, using the same account to sign in that you used above.