```Hello. I am trying to implement a progress bar ...

# react

[Dmitriy Malayev]

Hello. I am trying to implement a progress bar when a user tries to download a report and I'm getting errors

suspend fun downloadReportSection(
    reportFileName: String,
    section: EsgSection? = null,
    progressCallback: (Int) -> Unit
): ByteArray? {
    return try {
        val response = httpClient.get("${BackendReportingServiceURL}/esg-report/preview-report") {
            parameter("reportFileName", reportFileName)
            section?.let { parameter("section", it.name) }

            onUpload { bytesSentTotal, contentLength ->
                val progressPercentage = ((bytesSentTotal / contentLength.toDouble()) * 100).toInt()
                progressCallback(progressPercentage)
            }
        }
        if (response.status == HttpStatusCode.OK) {
            progressCallback(100) // 100% completion once done
            return response.readBytes()
        } else {
            null
        }
    } catch (e: Exception) {
        console.log("Error: ${e.message}")
        null
    }
}


            Box {
                Button {
                    variant = ButtonVariant.contained

                    onClick = {
                        mainScope.launch {
                            val pdfReport = downloadReportSection(
                                props.esgReportStateProps.reportFileName,
                                EsgSection.General,
                                progressCallback = {}
                            )
                            pdfReport?.let {
                                val blob = Blob(arrayOf(it), BlobPropertyBag("application/pdf"))
                                val url = URL.createObjectURL(blob)
                                val a = document.createElement("a") as HTMLAnchorElement
                                a.href = url
                                a.download = props.reportStateProps.reportFileName
                                a.click()
                            }
                        }
                    }
                    +"Preview"
                }
            }


Could not load content for  /kotlinx-coroutines-core/js/src/internal/CoroutineExceptionHandlerImpl.kt?6a41 (Fetch through target failed: Unsupported URL scheme; Fallback: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME)

Error_0 {message: 'Fail to fetch', cause: TypeError: Failed to execute 'fetch' on 'Window': Request with GET/HEAD method cannot have body.

[Joffrey]

Check the value you have for BackendReportingServiceURL. The error says the URL scheme is unsupported, or maybe this variable is just completely empty.