Follow below steps to achieve your requirement:

Create a .sh file under scripts folder in root directory.

./Scripts/myscript.sh:

#!/bin/bash
echo  "Hello from myscript.sh!"
echo  "This is a test file created by the script."  >  /tmp/testfile.txt
cat  /tmp/testfile.txt
exit  0

Use below function code in .NET 8.0 Isolated Azure functions to execute bash script by invoking .sh file in the function code.

Code Snippet:

[Function("Function1")]
public IActionResult Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
    _logger.LogInformation("C# HTTP trigger function processed a request.");
    _logger.LogInformation(Directory.GetCurrentDirectory());
    string scriptPath = Path.Combine("/home", "site", "wwwroot", "scripts", "myscript.sh");
    
    if (!File.Exists(scriptPath))
    {
        _logger.LogError($"Script file not found at {scriptPath}");         
    }

    var startInfo = new ProcessStartInfo
    {
        FileName = "/bin/bash",
        Arguments = scriptPath,
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        UseShellExecute = false,
        CreateNoWindow = true
    };

    try
    {
        using (var process = Process.Start(startInfo))
        {
            if (process != null)
            {
                string output = process.StandardOutput.ReadToEnd();
                string error =  process.StandardError.ReadToEnd();

                _logger.LogInformation($"Output: {output}");
                if (!string.IsNullOrEmpty(error))
                {
                    _logger.LogError($"Error: {error}");
                }

                 process.WaitForExitAsync();
            }
        }
    }
    catch (Exception ex)
    {
        _logger.LogError($"An error occurred while executing the script: {ex.Message}");
    }

    return new OkObjectResult("Success!");
}

Deploy the function to Azure function App with flex consumption plan.

Console Output:

Run the function and you will be able to execute the script using Azure function. Check the invocation logs for detailed output as below.

2024-12-13T10:52:30Z   [Information]   Executing 'Functions.Function1' (Reason='This function was programmatically called via the host APIs.', Id=58d00ce3-f7cb-4dad-9f2c-479e622cbed4)
2024-12-13T10:52:30Z   [Information]   C# HTTP trigger function processed a request.
2024-12-13T10:52:30Z   [Information]   /tmp/functionsstandbywwwroot
2024-12-13T10:52:30Z   [Information]   Output: Hello from myscript.sh!
This is a test file created by the script.
2024-12-13T10:52:30Z [Information] Executing OkObjectResult, writing value of type 'System.String'.
2024-12-13T10:52:30Z [Information] Executed 'Functions.Function1' (Succeeded, Id=c726dfa3-52f2-43b1-8121-5184c01cf74b, Duration=20ms)