How to blur pictures on iPhone 11 Pro?

If you mean that you want to "hide" your personal info on a screenshot, you can edit it using the instructions provided in this support guide:--> Use Markup on your iPhone, iPad or iPod touch – Apple Support

Regards

Giulio

Sorry, could you please better explain your needs?

Take a screenshot and post it here, so that we can understand what's happening:--> Take a screenshot on your iPhone – Apple Support

Regards

GIulio