Enable Developer Mode

This is required for anything sideloading related.

Warning: Enabling developer mode will reduce security, as noted in Apple documentation. However, it is required for sideloading apps, so it's a trade-off.

1. Go to Settings, scroll down until you see Privacy & Security.

2. Scroll to the bottom, where you should see the Developer Mode option. When you turn it on, you will be prompted to restart your device.