When I start project by dotnet run after going in to .sln directory, this function works correctly. If I go to the projectfolder/../bin/Release/netcoreapp3.1/publish and run with dotnet project.dll it still works correctly, but if I start this app as a service, this function does not work and catch writes this line:

Access to the path '/home/.../projectfolder/uploaded-images/3713579a-5b47-48f7-8666-9e0b3ded3bb1.jpg' is denied.

private async Task<FileSaveResult> SaveImage(IFormFile imageFile)
{
    if (!Directory.Exists(IMAGEUPLOADPATH))
    {
        Directory.CreateDirectory(IMAGEUPLOADPATH);
    }
    string postedFileExtension = Path.GetExtension(imageFile.FileName);
    string newName = Guid.NewGuid().ToString() + postedFileExtension;
    string newPath = Path.Combine(IMAGEUPLOADPATH, newName);
    try
    {
        using var fileStream = new FileStream(newPath, FileMode.Create);
        await imageFile.CopyToAsync(fileStream);
        return new FileSaveResult
        {
            ContentType = imageFile.ContentType,
            PhysicalAddress = newPath,
            IsSuccess = true
        };
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
        return new FileSaveResult();
    }
}

This is where i initiliaze IMAGEUPLOADPATH

public AdminController(..., IWebHostEnvironment environment,...)
{
    ...
    VIDEOUPLOADPATH = Path.Combine(environment.ContentRootPath, "uploaded-videos");
    IMAGEUPLOADPATH = Path.Combine(environment.ContentRootPath, "uploaded-images");
    ...
}

I start service with this command sudo systemctl start myprojectname.service

and this is the content of myprojectname.service file (I generally dont know the meanings of these lines).

[Unit]
Description=.....

[Service]
WorkingDirectory=/home/..../myproject
ExecStart=/usr/bin/dotnet /home/.../myproject/bin/Release/netcoreapp3.1/publish/project.dll
Restart=always
RestartSec=10
ProtectHome=off
KillSignal=SIGINT
SyslogIdentifier=myproject
User=www-data
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WntedBy=multi-user.target

How can I solve this problem? I am starting this project via a ssh connection. I can't close the command line because it kills the app.