Android Studio – Sending data from Fraggment_A in Activity 1 to Fragment_B in Activity 2

I have a Fragment_A on Activity_1 and whenever a Button is clicked in the Fragment_A I have to start Activity_2 witch have a Fragment_B

So i need to send a user_Id from the Fragment_A in Activity 1 to the Fragment_B in activity_2.
Is there any way to send the data directly from Frament_A in Activity_1 to Fragment_B in Activity_2?

I am a student , so i am a beginner and i did found this question here but i didn’t understand what to do to solve this
I did find some solution about interface but i didn’t know how to do it

i keep getting class_id null

Language : Kotlin

Class : ClassesAdapter

class ClassesAdapter(val c:Fragment,val l:android.content.Context? ,val classeslist: ArrayList<Classes>) : RecyclerView.Adapter <ClassesAdapter.ClassesViewHolder> (){
    lateinit var auth: FirebaseAuth
    lateinit var DataBase : DatabaseReference
    lateinit var DataBase2 : DatabaseReference
    lateinit var clipboardManager: ClipboardManager


    private lateinit var mListener :onItemClickListener

    interface onItemClickListener {

        fun onItemClick(position :Int)

    }

    /*fun setOnItemClickListener(listener : onItemClickListener){

       // mListener=listener

    }*/

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ClassesViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(R.layout.class_items2,parent,false)
        //return ClassesViewHolder(itemView,mListener)
        return ClassesViewHolder(itemView,)
    }


  
    
        override fun onBindViewHolder(holder: ClassesViewHolder, position: Int) {
            val currentitem = classeslist[position]
            holder.classname.text = currentitem.name
            holder.classrole.text = currentitem.role
    
            holder.itemView.setOnClickListener {
    
    
                val intent = Intent(l, DetailedClassActivity::class.java)
                intent.putExtra("classId", currentitem.class_id)
                l!!.startActivity(intent)
    
            }

Class : Acttivity2 who has the fragment iwant to send it the class_id`

 package com.example.myclass1
    
    import android.content.Intent
    import android.os.Bundle
    import android.widget.Toast
    import androidx.viewpager2.widget.ViewPager2
    import com.example.myclass1.databinding.ActivityDetailedClassBinding
    import com.google.android.material.tabs.TabLayout
    import com.google.android.material.tabs.TabLayoutMediator
    import com.google.firebase.auth.FirebaseAuth
    
class DetailedClassActivity : DrawerBaseActivity() {

    private lateinit var binding: ActivityDetailedClassBinding
    //lateinit var toggle: ActionBarDrawerToggle
    override lateinit var auth: FirebaseAuth

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding= ActivityDetailedClassBinding.inflate(layoutInflater)
        setContentView(binding.root)

        // add it to change the toolbar title's to the activity name
        val actionBar = supportActionBar
        if (actionBar != null) {
            val dynamicTitle: String = HomeActivity::class.java.simpleName
            //Setting a dynamic title at runtime. Here, it displays the current activity name
            actionBar.setTitle("Home")
        }


        // navigate between documents ,notification and chatroom  :  tabLayout
        val tablayout2 : TabLayout =findViewById(R.id.tab_layout2)
        val viewpager21 : ViewPager2 =findViewById(R.id.viewPager21)
        val adapter =PagerAdapter2(supportFragmentManager,lifecycle)
        viewpager21.adapter = adapter
        TabLayoutMediator(tablayout2, viewpager21) { tab, position ->
            when(position){
                0->{tab.text="Documents"}
                1->{tab.text="Note"}
                2->{tab.text="ChatRoom"}
            }
        }.attach()


       

    val intent=getIntent()
    var classId= intent.getStringExtra("classId")
      

fun getMyData(): String? {
    return classId
    }

    }
       

class : fragment B

   enter code here
     btnAddcourse.setOnClickListener {
                var nameofthecourse = Coursename.text.toString().trim()
                var course_id :String?=DataBase3.push().key
                
                var classId = arguments?.getString("classId")
               
                
                val dateofthecourse: String = formatTimeStamp()
    
                if (TextUtils.isEmpty(nameofthecourse)) {
                    // No name added
                    Coursename.error = "No name added !! Please enter the name of the class"
                }
                else{
                    courseList.add(Course(course_id,nameofthecourse,dateofthecourse,classId))
                    coursesAdapter.notifyDataSetChanged()
                    Toast.makeText(activity,"Adding Course Success", Toast.LENGTH_SHORT).show()
                    //Toast.makeText(activity,"class_id is null ", Toast.LENGTH_SHORT).show()
                    if (classId != null) {
                        addCourseToDataBase(course_id!!,nameofthecourse,dateofthecourse,classId)
                    }else{
                        Toast.makeText(activity,"class_id is null ", Toast.LENGTH_SHORT).show()
                    }
                }
            }