@ToyjoHa 

Hi, are you able to access the internet when you connect your phone/laptop directly to that AP signal? Do you need to do any set up on the phone/laptop?

As far as I know, some public Wi-Fi or portal network may require users to pass the portal authentication before surfing the internet, there should be no issue connecting to the internet when adding a wireless router to it as long as the authentication popup window shows up.
You may try to refer to the below instructions to configure the WR902AC as the Share Hotspot mode:
https://www.tp-link.com/support/faq/1501/

However, if the captive portal wireless network requires another login username and password, this WR902AC may not be compatible with that kind of wireless, which may have special requirements or limitations.

There is no problem from the network regarding passing the captive portal information along. The instructions that you gave are for wireless to wireless. I need from it to go from wireless to wired. @Kevin_Z 

@ToyjoHa 

Hi, if you want to connect the WR902AC to the computer with an Ethernet cable, you can configure it into a Client mode, here is the instruction:

https://www.tp-link.com/support/faq/2031/

ToyjoHa wrote

There is no problem from the network regarding passing the captive portal information along. The instructions that you gave are for wireless to wireless. I need from it to go from wireless to wired. @Kevin_Z