Laravel Query Scope Issue

I am using query scope its working fine when I use it like

Customer::phone($search)->agency()->get();

but give error when using agency scope first error: Non-static method App\Models\Customer::agency() cannot be called statically

Customer::agency()->phone($search)->get();

public function scopeAgency($query)
    {
        return $query->where('agency_id', session('agency_id'));
    }

    public function scopePhone($query, $search)
    {
        return $query->where('phone_no', 'like', '%' . $search . '%');
    }