Keyboard not popping up when I try to sign into Google account.

Greetings MarkWoro,

To help troubleshoot the keyboard behavior, test and see if the issue is cleared up after restarting your iPad and after checking for an update to iPadOS. Restarting and updating your iPad can clear up software issues such as the one being described.

You can check for an update to iPadOS by tapping Settings > General > Software Update. To restart your iPad, take these steps: Restart your iPad - Apple Support

"How to restart an iPad without a Home button

1. Press and hold either volume button and the top button until the power off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the top button until you see the Apple logo."

If the behavior is occurring with a third-party application, then reach out to the app developer for assistance with the issue. The following article shows how to reach out to an app developer: How to contact an app developer - Apple Support

"Contact the developer of an iOS, iPadOS, or watchOS app

1. Open the App Store on your iPhone, iPad, or iPod touch.
2. Search for the app, then tap it. If you can't find it, tap the account button  or your photo at the top of the screen, tap Purchased, tap "Not on this [device]," then tap the app.
3. The app's product page appears. Scroll to the Ratings & Reviews section, then tap App Support. If you don't see App Support, make sure that you're signed in with the correct Apple ID."

Kind regards.