How to off the line top corner of right right on iphone 13

You cannot. Note that it only appears on the lock screen of your iPhone. If you disable access to Control Center from your lock screen, then the line will be gone . . . but you won't have access to control center from your lock screen.

Settings -> Face ID & Passcode.

Scroll down to the section "ALLOW ACCESS WHEN LOCKED"

Turn off the switch next to "Control Center"

MooreD10 wrote:

You cannot. Note that it only appears on the lock screen of your iPhone. If you disable access to Control Center from your lock screen, then the line will be gone . . . but you won't have access to control center from your lock screen.

Settings -> Face ID & Passcode.

Scroll down to the section "ALLOW ACCESS WHEN LOCKED"

Turn off the switch next to "Control Center"

Good workaround!

NillSonowal wrote:

How to off this

You cannot.

You can let Apple know it's something you'd like to see here:

Product Feedback - Apple

You cannot. The line shows you where to drag down to get to the Control Center. Just like the line at the bottom of your lock screen shows you where to drag up to unlock the phone.