Error during creation a new organization

[ZedZipDev]

When I run the app and try to create a new organization I receive an error:
{"error":"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SNI_PN11, error: 26 - Error Locating Server/Instance Specified)"}

It is here

 private async Task<bool> TryAddCompany()
        {
            try
            {
                await mediator.Send(new UpSertTenantCommond() { TenantName = CompanyCommond.Name,TenantLogo=CompanyCommond.Logo });
                HttpContext.Response.Cookies.Append("tenant", CompanyCommond.Name);
                HttpContext.Session.SetString("tenant", CompanyCommond.Name);
                CompanyCommond.IsActive = true;
                CompanyCommond.Id = await mediator.Send(CompanyCommond);
            }
            catch (ValidationException validationException)
            {

                AddValidation(validationException);
                return false;

            }
            return true;
        }

How to fix it?