create a opportunity line member(Object) component with fields names Like Name , Date,quantity . and place in a Opp record page . and at the time of insert take button called add row , when click add row it will display the another row for that field line by line , click save button the data saved in that products

When the Product is added to the Opportunity , automatically opportunity status will update to Closed Won. 
How can we achieve with this using flow .

public class StringArrayTest { 
    
    public static List<string>  generateStringArray(integer size){
        
       List<String> arraylist = new List<String>(); 
        
        for(integer i=0;i<size;i++){
            arraylist.add('Test '+i);
        }
        
       return arraylist;
    }

} 

from Anonymous window :i call like below

StringArrayTest.generateStringArray(7);


its not showed any errors . its successfully executed.but its not returns a list in debug log.

public class StringArrayTest { 
    
    public static List<string>  generateStringArray(integer size){
        
       List<String> arraylist = new List<String>(); 
        
        for(integer i=0;i<size;i++){
            arraylist.add('Test '+i);
        }
        
       return arraylist;
    }

} 

from Anonymous window :i call like below

StringArrayTest.generateStringArray(7);


its not showed any errors . its successfully executed.but its not returns a list in debug log.

how to insert multiple records using dynamic apex in salesforce