Hi,
you can refer to TCP/IP stack demo examples. Download it from https://www.nxp.com/webapp/swlicensing/sso/downloadSoftware.sp?catid=SW32K3-REFSW-D and install it along right RTD version in S32DS. See package release note for installation steps.
The TCP/IP stack features a set of applications, which demonstrates key functionalities of this software product. One of application is the TCP echo server, using either Raw or Netconn API.
BR, Petr