BadMethodCallException Method Illuminate\Database\Query\Builder::input does not exist - laravel

Question

Am getting that error when submitting my form data for storing , Below is my approve_request_post function in controller.
public function approve_request_post(Request $request, $request_hash)
{
$request->validate([
'hosp_no' => 'required',
'transport_cost' => 'required',
'days' => 'required|numeric',
'per_diem' => 'required|numeric',
'service_type' => 'required',
'trans_mean' => 'required',
'cost_payable' => 'required|numeric',
'patient_age' => 'required|numeric',
'doctors_name' => 'required',
'appointment_date' => 'required|date',
'comment' => 'required',
]);
// Start transaction
DB::beginTransaction();
$request = ReferralRequestModel::where('request_hash', $request_hash)->firstOrFail();
$remark = new InsurerRemarksModel;
$remark->ir_hash = encrypt($remark->ir_id);
$remark->req_id = $request->request_id;
$remark->insurer_id = Auth::user()->insurers->insurer_id;
$remark->req_id = $request->request_id;
$remark->hosp_no = $request->input('hosp_no');
$remark->service_type = $request->input('service_type');
$remark->transport_cost = $request->input('transport_cost');
$remark->trans_mean = $request->input('trans_mean');
$remark->days = $request->input('days');
$remark->cost_payable = $request->input('cost_payable');
$remark->patient_age = $request->input('patient_age');
$remark->doctors_name = $request->input('doctors_name');
$remark->appointment_date = $request->input('appointment_date');
$remark->approval_date =Carbon::now();
$remark->ir_status = 'approved';
$remark->save();
//approvalrecord
$approval = new ApprovalModel;
$approval->req_id = $request->request_id;
$approval->approver_id = Auth::user()->id;
$approval->category = 'Insurer | Verified By: ';
$approval->status = 'Verified';
$approval->comment = $request->input('comment');
$approval->save();
//email to all medical team
if( !$remark->save() || !$approval->save() )
{
DB::rollback();
return back()->withInput(Input::all())->with('failure', 'Transaction Not Successful. Check the input data');
}
DB::commit();
return redirect('/insurer-view-submitted-requests')->with('success', 'Referral Request Approved Successfully');
}

Answer 1

Replace this line
$referral_model = ReferralRequestModel::where('request_hash', $request_hash)->firstOrFail();
Because you are replacing the $request with a model instance and trying to get the value using $request->input('hosp_no') something like that
$request->input('hosp_no') that method will try to get input method from your ReferralRequestModel
so replace the above line and use $referral_model where you want.
also suggest to use try , catch block for handle exception. because firstOrFail throw Illuminate\Database\Eloquent\ModelNotFoundException exception if data is not found