1. Software downloaded from elsewhere cannot be directly installed without jailbreak. You must go to the Apple Software Store or download it through third-party software to install it. Use the app store on your mobile phone; connect your mobile phone to a computer using a data cable. iTunes, you can download and use it if you have an Apple ID.

2. If you have jailbroken, you can download an itools on your computer, open it, connect it to your phone, select the application on the left, click Import, and select the app you downloaded to import it to your phone.

First connect the computer and device, open itunes, ensure the connection is smooth, and display your device

Click Store in the menu bar to authorize the computer with Apple ID.

Click the application in the menu bar, and then the interface as shown in the figure will appear.

Put the downloaded APP on the desktop and drag it directly into the iTunes application interface