QR Code Generator

For more information, you can visit this documentation:

https://www.e-iceblue.com/Tutorials/Spire.Barcode/Spire.Barcode-Program-Guide/Create-a-QR-Code-in-C.html

You can use LEADTOOLS Barcode SDK technology in your application. 
https://www.leadtools.com/sdk/barcode
For your use-case you can leverage the BarcodeWriter class to generate a QR barcode, add it to an image, and export that image to your database.

Here is some sample code:

// Write/Generate Barcode using LEADTOOLS SDK
using (RasterImage _image = RasterImage.Create(2550, 3300, 24, 300, RasterColor.White))
{
    BarcodeEngine _engine = new BarcodeEngine();
    BarcodeWriter _writer = _engine.Writer;

    // Set barcode options
    QRBarcodeData _qrData = BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.QR) as QRBarcodeData;
    _qrData.SymbolModel = QRBarcodeSymbolModel.Model1AutoSize;
    _qrData.Value = "QR Data 1";

    _qrData.Bounds = new LeadRect(0, 0, _image.ImageWidth, _image.ImageHeight);

    QRBarcodeWriteOptions _options = new QRBarcodeWriteOptions();

    _options.GroupNumber = 0;
    _options.GroupTotal = 0;
    _options.HorizontalAlignment = BarcodeAlignment.Near;
    _options.VerticalAlignment = BarcodeAlignment.Near;
    _options.XModule = 30;
    _options.ECCLevel = QRBarcodeECCLevel.LevelL;

    // Write image to barcode
    _writer.WriteBarcode(_image, _qrData, _options);
    
    // Save image
    using (RasterCodecs codecs = new RasterCodecs())
        codecs.Save(_image, @"FILE PATH TO OUTPUT IMAGE", RasterImageFormat.Png, 0);
}

Hello Try below links

https://www.c-sharpcorner.com/article/creating-qrcode-in-asp-net-core/

https://www.c-sharpcorner.com/article/generate-qr-code-and-save-into-the-database/

https://www.aspsnippets.com/questions/208874/Generate-QR-code-Image-and-save-in-Database-using-C-and-VBnet-in-ASPNet/

You can search and install Free Spire.Barcode via NuGet(https://www.nuget.org/packages/FreeSpire.Barcode/), then use the below code to generate QR code easily:

using Spire.Barcode;
using System.Drawing;


namespace QRCode
{
    class Program
    {
        static void Main(string[] args)
        {
            BarcodeSettings settings = new BarcodeSettings();
            settings.Type = BarCodeType.QRCode;

            settings.Data = "Hello 123456789";
            settings.Data2D = "Hello 123456789";
            settings.QRCodeDataMode = QRCodeDataMode.AlphaNumber;
            settings.X = 1.0f;
            settings.QRCodeECL = QRCodeECL.H;

            BarCodeGenerator generator = new BarCodeGenerator(settings);
            Image image = generator.GenerateImage();
            image.Save("QRCode.png");
        }
    }
}

For more information, you can visit this documentation:

https://www.e-iceblue.com/Tutorials/Spire.Barcode/Spire.Barcode-Program-Guide/Create-a-QR-Code-in-C.html