By default, the Safari will not show favicon in iPhone. Press the first icon at the bottom of the Safari after you open a website, and you cannot see the favicon of that site.
If you want to Safari to show favicon, then follow the below steps.
Enable Favicon in iPhone Safari
Step 1: Open Settings.
Step 2: Tap Safari.
Step 3: In the Tabs section, you can see Show Icons in Tabs.
Step 4: Beside it, you can see a toggle switch. Enable it.
Note: To revert, follow the above steps but make sure to disable instead of enabling.