Unfortunately, what I need is not to append flags, but to remove the existing ones which I can't find any way to do. I can do the following in my main.cpp file: qDebug() << qgetenv("QTWEBENGINE_CHROMIUM_FLAGS"); qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--anything-i-want"); But the output from the getenv is just "", so I'm not sure where its getting the flags from. The addition of the chromium flag is indeed working, but the final command line shown by chrome://gpu is this: (which includes the --disable-gpu at the end) webglcpptest --anything-i-want --browser-subprocess-path=/usr/lib/x86_64-linux-gnu/qt5/libexec/QtWebEngineProcess --application-name=webglcpptest.red --no-sandbox --enable-threaded-compositing --disable-speech-api --enable-features=AllowContentInitiatedDataUrlNavigations,NetworkServiceInProcess,TracingServiceInProcess --disable-features=MojoVideoCapture,FontSrcLocalMatching,UseSkiaRenderer,DnsOverHttpsUpgrade,ConsolidatedMovementXY,InstalledApp,BackgroundFetch,SmsReceiver,WebPayments,WebUSB,PictureInPicture --disable-gpu It doesn't seem possible to override the existing flag with another, I've tried things like --disable-gpu=false and so on, I've tried finding a way to comment out the rest of the flags, even tried a buffer overflow to get rid of the last flag... So I have to find where the flags are coming from and remove them.

@javperan yup, looks like the template has changed since. Currently, I'd probably change line 360: await serviceWorkerLoader.loadServiceWorker(serviceWorker).catch(e => { to: await serviceWorkerLoader.loadServiceWorker(null).catch(e => { Basically, I'm trying to find the section of the code that checks for the service worker, which is in line 117: loadServiceWorker(settings) { if (settings == null) { // In the future, settings = null -> uninstall service worker? console.debug("Null serviceWorker configuration. Skipping."); return Promise.resolve(); } ... Here you can see it checks if 'settings' is null, and seems to handle it gracefully, so any way you can force it to run through that if statement would work fine.

@ari I see. That makes more sense. I guess the developer of Cinny or Florian.

FWIW, my Yubikey works fine on my Volla phone fyi, it is recognized as a keyboard though from what i've seen

@ari Maybe it has something to do with chromium flags? Morph uses C++ though not exactly the clickable template.

Finally figured it out. Well... kind of. The solution is to not use the Webview, but instead WebEngineView, and make sure to include the onFeaturePermissionRequested method. In conclusion, just steal the code from the discord app.