Icons work on pc1, but give unknown on another pc.

Hi all

I am building a shiny app. The icons are good visualised on my system, but when the file is opened on another pc (with internet). The icons give something this :

This is how I code the icons in the UI:

 tabPanel("Distribution based on MATERIAL", icon = icon("fa-regular fa-vial", verify_fa = FALSE)

This is the website where I can find the icons of chose:

I already look some info up and found this:

#Connection for the icons:

I created an account online and connected the script to my account by that number, but it doesn't help.

Otherwise I don't have done something special to get those icons on my pc.

Thanks for the help in advance!