Uploading base64 encoded CSV file

[adhossain]

Description

I am trying to upload a CSV file using V2 API. the file is propoerly encoded with Base64. I am using Power Automate to perform the process. But I am receiving HTTP error 400 with description "base64Encoded": "Invalid content"

Steps to Reproduce

Step 1: Set Up Power Automate Flow
Trigger:

Start with a trigger that suits your needs, such as "When a file is created or modified in a folder" in SharePoint.
Initialize Variables:

Add an action to initialize a variable to store the CSV content.
Name: CSVContent
Type: String
Value: Leave it empty for now.
Get File Content:

Use the "Get file content" action to retrieve the CSV file from SharePoint.
Site Address: Your SharePoint site address.
File Identifier: The identifier of the file you want to retrieve.
Set CSV Content Variable:

Use the "Set variable" action to store the CSV content in the CSVContent variable.
Name: CSVContent
Value: @string(outputs('Get_file_content')?['body'])
Step 2: Convert File Content to Base64
Convert File Content to Base64 (Compose 1):

Add a "Compose" action to convert the file content to Base64.
Inputs: @base64(variables('CSVContent'))
Trim Base64 String (Compose 2):

Add another "Compose" action to ensure there are no extra characters or spaces in the base64 string.
Inputs: @Trim(outputs('Compose_1'))
Step 3: Prepare the Kobo API v2 Request
HTTP Action:
Add an HTTP action to send a POST request to the Kobo API v2.
Method: POST
URL: https://URL/api/v2/assets/form_ID/files/
Headers:

{ "Authorization": "Token YOUR_KOBO_API_TOKEN", "Content-Type": "application/json" }

Body:
{ "user": "https://URL/api/v2/users/YOUR_USERNAME/", "asset": "https://URL/api/v2/assets/form_ID/", "description": "Description of the file", "base64Encoded": "@outputs('Compose_2')", "metadata": { "filename": "ben_database.csv" } }

Expected behavior

The file should be upload propeorly without error

Actual behavior

HTTP error 400 with description "base64Encoded": "Invalid content"

Additional details

I am using Power Automate and Sharepoint