can't create a udf function

After some trying, I figured it out. Parameters are unlike measures, context transition doesn't take place automatically. So I need to force the parameter to take into consideration of the evaluation context by adding calculate(). Below is the correct DAX query

DEFINE
     
FUNCTION MOV_AVG_UDF = (d:int64 expr)  =>
    round(averagex(
window(d,REL,0,REL, summarize(fact_stocks,Dim_Date[Date],dim_stocks[Ticker]), orderby(Dim_Date[Date]), partitionby(dim_stocks[Ticker])), calculate(average(fact_stocks[Close]))),
2)


EVALUATE
ADDCOLUMNS(
    FILTER(
        VALUES(Dim_stocks[Ticker]),
        Dim_stocks[Ticker] IN {"AAPL"}
    ),
    "udf", calculate(MOV_AVG_UDF(-19)))

video about parameter and context transition (min 19):  https://www.youtube.com/watch?v=60jUmTxpxbw&t=815s