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Sending Microphone recording via Microsoft Flow using HTTP POST only works for desktop and not mobile



I'm having issues trying to send audio recorded from PowerApps microphone to custom made API using Microsoft flow HTTP POST. I have successfully implemented this solution using the power apps on browser using the following code :


for microphone OnStop function I'm calling the following functions : 

Set(strB64Audio, Mid(tmpJson,25,Len(tmpJson)-25));


and for my submit button I'm calling flow which takes the base64 string parameter and send it via HTTP POST body


I have tried the same solution using the mobile app and it does not seem to be working. The string send to API is "dio8425894081742020559.3gp" which is not a base64 String. 


Can you please help me? Or perhaps guide me to documentation? Basically what I'm trying to do is record audio on PowerApps ,and post this  recorded audio to some server using the HTTP POST. I saw couple articles about converting the audio in to base64String using the JSON(Microphone1.Audio,IncludeBinaryData) function and then sending the string via Microsoft Flow.



Thanks for your time,

Community Support
Community Support

Hi @shervinmirsaeid ,


Can you please share the related configuration in your Flow? 


Also you should delete the ";" at the end of your formula.




Community Support Team _ Mona Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

I have attached a photo of my flow configuration to this message and I have also explained the steps below :


1) first event is PoowerApps to trigger the flow


2)Initialize variable from PowerApps trigger body 

Type : String  

Name : AudioBase64String

Value : triggerBody()['initilizevariable_Value']


3) HTTP method POST with following body :

"AudioBase64String": @{variables('AudioString')}

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