I get error on _logger showing(The Name _logger doesn't exists )

Make sure that you have declared and instantiated the _logger object properly before using it. You might need to create an instance of a logging library, like ILogger, and assign it to the _logger variable.

using Microsoft.Extensions.Logging;


public class YourClass
{
    private readonly ILogger _logger;

    public YourClass(ILogger logger)
    {
        _logger = logger;
    }

    public ReturnType YourMethod()
    {
        try
        {
            // Your code that might throw an exception
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "An error occurred");
        }

        return xyz;
    }
}