I want to open a port so others can connect to me and we can form a server
I used UPNP on my TP router but the port still shows as closed for me.
Others cannot connect to me either.

I tried creating a virtual server using TP router interface, entering the same port number for TDP and UDP, still closed.
I made sure to use my local ip address for the computer as the internal address.
Not sure what is going on.

I don't have a firewall, just use windows defender with malwarebyte.

You may need to configure the router to forward inbound connections to a local IP address.

ShieldsUp! is a great method for remotely testing which ports are 'open', 'closed', or, purposefully non-responsive.

After visiting the initial page, just under 'You may select any service from among those listed above . . .', there is a field to input a given TCP port number. After doing so, you may simply select 'User Specified Custom Port Probe'.

This is quite useful when altering router settings (and, for whichever reason, a trusted third party familiar with Nmap is unavailable).

If you would prefer, we may thoroughly explore this topic through private message. : )

What about Windows' built-in firewall? Is it active?

Win 7: Settings > Windows Firewall
Win 10: Settings > Update & Security > Windows Security > Firewall & network protection
Win 11: Settings > Privacy & Security > Windows Security > Firewall & network protection

Haven't done this yet. Will give this a try.
Edit: Checkmark next to the app name = allowed?

I have the checkmark on the left to the app checked
and both checkmarks under public and private categories on the right checked.

Have you also taken a look at https://portforward.com/router.htm ?

nice site, but my router is ax50
I don't see it on here.
https://portforward.com/tp-link/
I looked at their page for ax10 but the instructions don't match

Have you consulted the AX50 user guide?
https://www.tp-link.com/us/user-guides/archer-ax50_v1/chapter-10-nat-forwarding

Maybe double-check the settings for Virtual Server and/or UPNP?
But don't put your computer into DMZ because then it's completely exposed to the Internet.

[edit] also found this:
https://www.tp-link.com/us/support/faq/1379/

For Device IP, it is the IPv4 under ipconfig, right?

In most cases: Yes!
Unless:
- you have multiple hardware network adapters. (My mainboard comes with two independent network controllers.)
- Or have virtualization software (VMWare, VirtualBox, ...) installed which creates another virtual LAN with virtual adapters.
- Or use VPN software of any kind, which reroutes your internet traffic and/or also creates virtual LAN adapters.

To be sure, check your router interface again. There should be an overview of your local network, i.e. which devices are connected and what IPs they got assigned.