Hello Maryursula,
Welcome to Apple Support Communities!
We want to help resolve this software issue so you can enter your password when using the iPad.
First, please check for any pending iOS updates, which can help make sure the software is working as expected. This Apple Support page can help get those updates installed: Update your iPhone, iPad, or iPod touch - Apple Support
"Update your iPhone or iPad wirelessly
- Back up your device using iCloud or your computer.
- Plug your device into power and connect to the internet with Wi-Fi.
- Go to Settings > General, then tap Software Update.
- If you see more than one software update option available, choose the one that you want to install.
- Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do."
Restart your iPad as well to see if that helps quickly resolve the issue.
We hope these steps can help resolve the issue so you can use the App Store without any issue.
Cheers!