Hey there clive199,
Thanks for reaching out to Apple Support Communities. I understand you’re having issues with the iPhone keyboard covering the screen so you’re not able to see what you’re typing. I’ll be happy to help with this.
Is this happening with multiple apps or just a specific few? If you’re not sure test with a few apps. It may help if you force close the app you’re using and restart your iPhone as well:
How to force an app to close on your iPhone, iPad, or iPod touch
Restart your iPhone
Also, check for updates to your iPhone and the app as well:
Update your iPhone, iPad, or iPod touch
Update apps or use automatic downloads
If the issue continues, delete one of the affected apps and restart your iPhone. Install the app back on your device, then test again.
Let me know if this helps.