I'm trying to do exactly what OP was trying in https://community.tp-link.com/en/smart-home/forum/topic/538506 However I have a different router and the solution doesn't seem to apply. My ER router is

I have created a Client-to-site VPN PPTP server on my ER7212PC router. This router has the WAN IP of 192.168.2.161. It's wan is connected to a Bell router/modem. This router/modem does have TCP 1723 (