Hey there becci65,
Let's team up to get his iPhone keyboard working right in Safari.
From the details you provided, the issue is unclear with what's exactly occurring. You mentioned you're trying to send an email from within Safari, but we do not see this on the screenshot you sent from his iPhone. What we do see is that he was able to enter a search for 'jd sports', so we're confused as to the exact issue. The more details you provide, the better equipped we'll be to assist.
Has any steps been tired, like a restart as one example?
As they have a compatible model, the latest version is iOS 15. You can verify this within Settings > General > About. Here's a link that'll show how to first back up, then Update your iPhone, iPad, or iPod touch.
Take care!