Access to HAOS system files on file editor

I have been trying for a while to replace the icon of HAOS in the login page with my own icon, my system is installed on a mini pc, and I was trying to access the system or server files (whatever you call it) on Studio Code Server but it seems that the access is limited.
however, forgive my limited experience and if you can help, please leave me a comment or contact me on [email protected]