We understand you'd like to resume a software download. We're happy to offer some guidance.
Based on the screenshot you attached, it looks like it is directing you to connect your phone to a Wi-Fi network so it can resume the download. You can use these steps to connect to a Wi-Fi network: Connect to Wi-Fi on your iPhone, iPad, or iPod touch
Update your iPhone, iPad, or iPod touch
Hope this helps. Cheers!