2. Installing the SSL certificate on iOS
Open Safari on iPhone (or iPad)
Enter: chls.pro/ssl and press Go

The following prompt is displayed:

Click Allow
Go to Settings
Open Profile Downloaded
Install Profile screen will open:

Click Install and enter your Passcode when asked
A Warning is shown:

Tap Install again, then tap Install in popup:

Afterward, the following screen with a green Verified checkmark should show:

Click Done
Open Settings App
Go to General
Open About
Scroll down to Certificate Trust Settings:

Click on Certificate Trust Settings >
The following screen is shown:

Turn on the Switch next to Charles Proxy CA (...)
Click Continue on the Root Certificate Prompt

Verify that the Switch is On and has a green background visible.

This completes the iPhone / iPad setup.
You are almost finished. Just one more step before the short task. 😎