Applying own fonts to all plots

[Slavek]

I've been looking for a way of applying my own fonts to the plots but all I can see is related to default windows fonts. I had a request from my client to apply his provided fonts to all documents I produce. Applying that to MS Office was simple because I cimply toppied new fonts to my machine. Unfortunately, I cannot use them in R plots.
What code should I use to upload "My onw fonts" to my plots?
I've tried a few solotions such as this one:

library(extrafont)
font_import() # import all your fonts
fonts() #get a list of fonts
fonttable()

but it does not work. My fonts are saved in the same place as all other windows fonts.
Can you help please?

[andresrcs]

if you are on windows you have to import your fonts this way

library(extrafont)
loadfonts(device = "win")

[Slavek]

Thank you. How can I check if my font is listed?

[andresrcs]

Search by font name

library(extrafont)
font_import()
font_name <- "UnBatang"
grep(font_name, fonts(), value = TRUE)