Tips on how to Construct a QR Code Android App utilizing Firebase?

<?xml model="1.0" encoding="utf-8"?>

<LinearLayout 

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    android:background="@drawable/back_qr"

    android:gravity="center_horizontal"

    instruments:context=".MainActivity">

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textual content="MY QR CODE"

        android:textSize="24sp"

        android:textStyle="daring"

        android:fontFamily="@font/daring"

        android:textColor="@shade/white"

        android:layout_marginTop="50dp"/>

    <androidx.cardview.widget.CardView

        android:layout_marginTop="35dp"

        android:layout_width="290dp"

        android:layout_height="350dp"

        app:cardCornerRadius="25dp">

        <ImageView

            android:id="@+id/img_qr"

            android:layout_width="match_parent"

            android:layout_height="match_parent"

            android:scaleType="fitCenter">

        </ImageView>

    </androidx.cardview.widget.CardView>

    <androidx.cardview.widget.CardView

        android:layout_width="300dp"

        android:layout_height="80dp"

        android:layout_marginTop="20dp"

        app:cardCornerRadius="50dp"

        android:backgroundTint="#5754D3">

        <RelativeLayout

            android:layout_width="wrap_content"

            android:layout_height="wrap_content">

            <com.google.android.materials.floatingactionbutton.FloatingActionButton

                android:layout_width="43dp"

                android:layout_height="43dp"

                android:id="@+id/btnQr"

                android:layout_marginLeft="17dp"

                android:layout_marginTop="20dp"

                type="@type/floating_yellow">

            </com.google.android.materials.floatingactionbutton.FloatingActionButton>

          <TextView

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:layout_marginTop="15dp"

                android:textual content="Generate Your Qr Code"

                android:layout_marginLeft="80dp"

                android:textColor="@shade/white"

                android:textStyle="daring"

                android:fontFamily="@font/daring"

                android:textSize="16sp">

            </TextView>

                <EditText

                    android:id="@+id/edtgen"

                    android:layout_width="wrap_content"

                    android:layout_height="wrap_content"

                    android:trace="Enter your Part Right here"

                    android:background="@null"

                    android:layout_marginTop="45dp"

                    android:layout_marginLeft="80dp"

                    android:textColor="@shade/white"

                    android:textColorHint="@shade/white"

                    android:textSize="12sp" />

        </RelativeLayout>

    </androidx.cardview.widget.CardView>

    <com.google.android.materials.floatingactionbutton.FloatingActionButton

        android:id="@+id/btnScan"

        android:layout_width="50dp"

        android:layout_height="50dp"

        type="@type/floating_green"

        android:layout_marginTop="60dp"

        android:outlineSpotShadowColor="@shade/black"

        android:outlineAmbientShadowColor="@shade/black"/>

</LinearLayout>