Why does Jetbrains font not load in file?

Trying to practice using different fonts in Kivy code. I am getting this error: OSError: File JetBrainsMono-Regular.ttf not found

main.py

kv ='''
MDScreen:
    MDLabel:
        text: "JetBrainsMono"
        halign: "center"
        font_style: "JetBrainsMono"
        
'''

from kivy.core.text import LabelBase
from kivy.lang  import Builder
from kivymd.app import MDApp
from kivymd.font_definitions import theme_font_styles

class MainApp(MDApp):
    def build(self):
        LabelBase.register(
            name= "JetBrainsMono",
            fn_regular= "JetBrainsMono-Regular.ttf")

        theme_font_styles.append('JetBrainsMono')
        self.theme_cls.font_styles["JetBrainsMono"] = ["JetBrainsMono", 16, False, 0.15,]

        return Builder.load_string(kv)

MainApp().run()

Thanks