Get absolute file path on the machine. ASP.NET Core

I am using AWS S3 SDK and I want to upload the files from my WEB API to the Bucket. It is working perfectly normal if the provided filePath is of the sort C:\User\Desktop\file.jpg, but if I use Path.GetFullPath(file.FileName) It is looking for the .jpg file inside my project folder. How can I get the absolute path on the machine, not the path in the project folder.

public async Task UploadFileAsync(IFormFile file, string userId)
    {
        var filePath = Path.GetFullPath(file.FileName);
        var bucketName = this.configuration.GetSection("Amazon")["BucketName"];
        var accessKey = this.configuration.GetSection("Amazon")["AWSAccessKey"];
        var secretKey = this.configuration.GetSection("Amazon")["AWSSecretKey"];
        var bucketRegion = RegionEndpoint.EUWest1;

        var s3Client = new AmazonS3Client(accessKey, secretKey, bucketRegion);

        try
        {
            var fileTransferUtility =
                new TransferUtility(s3Client);

            using (var fileToUpload =
                  new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {
                await fileTransferUtility.UploadAsync(fileToUpload, bucketName, file.FileName);
            }

            await this.filesRepository.AddAsync(new FileBlob
            {
                Name = file.FileName, 
                Extension = file.FileName.Split('.')[1],
                Size = file.Length,
                UserId = userId,
                UploadedOn = DateTime.UtcNow,
            });
            await this.filesRepository.SaveChangesAsync();
        }
        catch (AmazonS3Exception e)
        {
            Console.WriteLine(e.Message);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

path i get when i use GetFullPath when i should be getting C:\Users\Pepi\Desktop\All\corgi.png

I am sure that I am missing a lot of things here but in order for it to work i need the path to the file on the machine. If i try to escape using filepath and upload the file itself through memoryStream S3 says access denied.