Trying to get dynamic relationship in Laravel 6

model.php

<?php

// InventoryEmail Model

public function firstReply()
{
    return $this->belongsTo(InventoryEmail::class, 'first_reply_id', 'id');
}

public function scopeWithFirstReply(EloquentBuilder $query)
{
    $query->addSelect([
        'first_reply_id' => function (Builder $query) {
            $query->select('id')
                  ->from('emails as inbound')
                  ->whereColumn('inbound.id_account', 'emails.id_account')
                  ->whereColumn('inbound.id_listing', 'emails.id_listing')
                  ->whereColumn('inbound.id_type_direction', INBOUND)
                  ->whereColumn('inbound.id_type_communication', COMM_INBOUND)
                  ->limit(1);
        },
    ])->with('firstReply')->get();
}