Encountering Error While Using FontAwesome

[jagpreetrahi]

Hi Everyone, I hope you're doing well!
My name is Jagpreet Singh, and I’m a Full-Stack Developer from the Indian subcontinent. Recently, I came across an application and started exploring it to better understand how it works.
While using FontAwesome, I encountered an issue that I'd like to share for insights. Below are the snapshots.
I would love to better understand the structure, workflow, and best practices of FontAwesome to eventually contribute meaningful value to the project.