How to send custom headers from mvc project to a web api project?

I have two applications running together at the same time. In my mvc project I have a middleware that will use TempData in order to pass the values of username and ipAddress and add it to the response headers. What I am trying to do is with those headers that are added in the middleware of the mvc project is to pass those headers over to the web api project so I can be able to use the username and ipaddress and have the same correlationid. How can I send/forward those custom headers that are in the mvc project over to the web api project?

Middleware in mvc project:

public class CorrelationIdMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger _logger;
    private readonly ITempDataDictionaryFactory _tempDataDictionaryFactory;
    public CorrelationIdMiddleware(RequestDelegate next, ILoggerFactory loggerFactory, ITempDataDictionaryFactory tempDataDictionaryFactory)
    {
        _next = next;
        _logger = loggerFactory.CreateLogger<CorrelationIdMiddleware>();
        _tempDataDictionaryFactory = tempDataDictionaryFactory;
    }

    public async Task Invoke(HttpContext context)
    {
        string correlationId = null;
        string userName;
        string ipAddress;

        var tempData = _tempDataDictionaryFactory.GetTempData(context);

        var key = context.Request.Headers.Keys.FirstOrDefault(n => n.ToLower().Equals("x-correlation-id"));
        if (!string.IsNullOrWhiteSpace(key))
        {
            correlationId = context.Request.Headers[key];
            _logger.LogInformation("Header contained CorrelationId: {@CorrelationId}", correlationId);
        }
        else
        {
            if (tempData.ContainsKey("username") && tempData.ContainsKey("ipaddress"))
            {
                userName = tempData.Peek("username").ToString();
            
                ipAddress = tempData.Peek("ipaddress").ToString();

                context.Response.Headers.Append("X-username", userName);
                context.Response.Headers.Append("X-ipAddress", ipAddress);
            }

            correlationId = Guid.NewGuid().ToString();
            _logger.LogInformation("Generated new CorrelationId: {@CorrelationId}", correlationId);
        }
        context.Response.Headers.Append("x-correlation-id", correlationId);
        using (LogContext.PushProperty("CorrelationId", correlationId))
        {
            await _next.Invoke(context);
        }
    }
}

now moving to my web api project:

At first I had the same exact code for my mvc middleware but it never entered the if statement for the tempdata.containkey so I removed tempdata implementation.

public class CorrelationIdMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger _logger;
    public CorrelationIdMiddleware(RequestDelegate next, ILoggerFactory loggerFactory)
    {
        _next = next;
        _logger = loggerFactory.CreateLogger<CorrelationIdMiddleware>();
    }

    public async Task Invoke(HttpContext context)
    {
        string correlationId = null;

        var key = context.Request.Headers.Keys.FirstOrDefault(n => n.ToLower().Equals("x-correlation-id"));
        if (!string.IsNullOrWhiteSpace(key))
        {
            correlationId = context.Request.Headers[key];
            _logger.LogInformation("Header contained CorrelationId: {@CorrelationId}", correlationId);
        }
        else
        {
            correlationId = Guid.NewGuid().ToString();
            _logger.LogInformation("Generated new CorrelationId: {@CorrelationId}", correlationId);
        }
        context.Response.Headers.Append("x-correlation-id", correlationId);
        using (LogContext.PushProperty("CorrelationId", correlationId))
        {
            await _next.Invoke(context);
        }
    }
}