Use "Async" suffix in names of methods that return an awaitable type (https://github.com/Microsoft/vs-threading/blob/main/doc/analyzers/VSTHRD200.md)

Cancel synchronously blocks. Await CancelAsync instead. (https://github.com/Microsoft/vs-threading/blob/main/doc/analyzers/VSTHRD103.md)

Possible null reference argument for parameter 'plainText' in 'QRCodeData QRCodeGenerator.CreateQrCode(string plainText, ECCLevel eccLevel, bool forceUtf8 = false, bool utf8BOM = false, EciMode eciMode = EciMode.Default, int requestedVersion = -1)'.