Open the Photos app
Select the photo you want to edit
Tap Edit
Use the Depth Control slider if available to reduce background sharpness
Use Portrait mode photos for built-in background blur
Tap the adjustment tools
Lower Sharpness if needed
Lower Definition if needed
Lower Clarity if needed
Use a third-party app like Snapseed, Photoshop Express, or Blur Photo Editor
In the app, choose the blur tool
Brush or apply blur to the area you want
Save the edited photo
Use Markup only for simple censoring with shapes or stickers
Save a copy after editing