Where do you see the message that no devices are supported? Is it a build error? If so, please send the full error.

Using Firebase with cordova-plugin-firebasex works well.

This might be obvious, but are you sure you are using the inappbrowser open method? (you need to replace window.open with cordova.InAppBrowser.open)

https://github.com/apache/cordova-plugin-inappbrowser#windowopen

It might work using setInterval as described here:
https://developer.mozilla.org/en-US/docs/Web/API/Vibration_API

You can still use API level 29 on the version of cordova-android used by Monaca.

Make sure your setting is within the <platform name=“android”> section of your config.xml. You can also try setting android-targetSdkVersion to 29.

How about this?
https://www.w3schools.com/howto/howto_css_flip_image.asp

You could try setting the target argument of the open method:
https://github.com/apache/cordova-plugin-inappbrowser#cordovainappbrowseropen

This can be used to open in the inapp browser or in the system browser.

Ah yes, you should also make sure you are using Cordova 9 with Monaca (this it the default). You can check in the Cordova Plugin Settings page what Cordova version you are using.

You can see the differences in the plans here:

https://monaca.io/pricing-detail.html

In the Android section of your config.xml, try adding the following line (or amending if you already have this line):

<preference name=“android-minSdkVersion” value=“29” />