The code below will enable you to change the padlock icon that appears on your lock screen (when you have certain sections of your app locked).
1) While in your App Manager click Colors.
2) Scroll down to the Advanced Css box and enter the following code. If there is already code in the box do not delete it! Simply add this code “below” the last character of code in the box.
/** Begin change padlock image*/
[state="padlock-view"] .item.item-body.item-custom.text-center {
background-image: url(https://photos1.blogger.com/blogger/2905/2056/320/rowanatkinson.jpg) !important;
background-position: 50%;
height: 300px;
background-repeat: no-repeat;
}
.padlock .item.item-body i {
font-size: 0px;
}
/** End change padlock image*/
3) Click “Save”
NOTE: In url() you can add the Url of the image you want to use. However, the image should not be too large (around 256×256 in size).