Avg() column from Relationship

TextColumn::make('saleItems_avg_price')->avg([ 
'saleItems' => fn (Builder $query) => $query->where('product_id', equalTo('id')),], 'price')

Schema::create('sale_items', function (Blueprint $table) {
$table->id();
$table->foreignId('sale_id')
                ->constrained('sales')
                ->cascadeOnDelete();
$table->foreignId('product_id')
                ->constrained('products')
                ->cascadeOnDelete();
$table->unsignedBigInteger('quantity');
$table->decimal('unit_price');
$table->decimal('price', 10, 2)
                ->nullable();
$table->timestamps();

 Schema::create('products', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->string('sku')
                ->unique()
                ->nullable();
$table->longText('description')->nullable();
$table->unsignedBigInteger('quantity')->nullable();
$table->decimal('unit_cost', 10, 2)->nullable();
$table->boolean('is_visible')->default(false)->nullable();
$table->enum('type', ['flower', 'edible', 'etc'])->nullable();
$table->unsignedBigInteger('sold')->nullable();
$table->timestamps();