Error "no *.cm, *.mlb, or millet.toml files found in this directory" in VS code using SML

Question

I installed WSL, SML and Millet extensions in VS code for a course I'm taking, I have 2 files with code when I'm trying to run them I get an error: "uncaught exception SysErr [SysErr: access: cannot get file attributes] raised at: Basis/Implementation/Win32/os-filesys.sml:32.30-32.74"

My files are: hw1.sml

fun is_older (d1 : int*int*int, d2 : int*int*int) = 
    if (#1 d1) > (#1 d2) andalso (#2 d1) > (#2 d2) andalso (#3 d1) > (#3 d2)
    then true
    else false
    
fun number_in_month (ds : (int*int*int) list, m : int) =
    let
    fun count (ds : (int*int*int) list) = 
        if null ds
        then 0
        else if (#2 (hd ds)) = m 
            then 1 + count (tl(ds))
            else count (tl(ds))
    in
    count ds
    end

hw1test.sml

use "hw1.sml";

(* Homework1 Simple Test *)
(* These are basic test cases. Passing these tests does not guarantee that your code will pass the actual homework grader *)
(* To run the test, add a new line to the top of this file: use "homeworkname.sml"; *)
(* All the tests should evaluate to true. For example, the REPL should say: val test1 = true : bool *)


val test1 = is_older ((1,2,3),(2,3,4)) = true

val test2 = number_in_month ([(2012,2,28),(2013,12,1)],2) = 1

I also have 2 files I created to solve this error but I still get the error. the other 2 files are:

millet.toml

version = 1
workspace.root = "sources.mlb"

sources.mld

hw1test.sml
hw1.sml

I tried also reinstalling vs code and SMLNJ but still no good.