How to Locate TP Link Switches on a LAN Network

Do you want to scan your network?
What is the issue

Are you asking that you need to access the switch for management purposes? if yes

most of these switches comes with deafult ip address 192.168.0.1 ( username : admin / Pass : admin )

just configure your pc with ip from what same range ( for example 192.168.0.2 ) and connect your pc directly to the switch

and from the Brower enter the default ip of the switch to login

https://www.tp-link.com/us/configuration-guides/accessing_the_switch/?configurationId=18231#save_the_configuration_file_2_2

if you are asking that you have many of TP link switches connected to your network and need to know where is these switch and to which port of connected

in this case , you need to check your network switches ( mac address table )  entries and look for MAC addresses which belong to TPlink , how ?

as you know each MAC address consist of 48 bits , first 24 belong to vendor for example cisco , juniper , tplink ..etc and second 24bit belong to series .

so after that you need to look for these MAC address and lookup to know which of these mac addresses belong to tplink https://aruljohn.com/mac.pl

below example of mac address table

Note : your switches must be managed to allow you to check mac address table .

simplest way , if these tplink switches has lldp enabed ( Link Layer Discovery Protocol  ) in this case just login your network switches and check lldp neighbors this will give you what is the device type and to which port connected

I can't login to them or find them on the network. When they were installed in 2016 they came with a network scan tool. I would run it, the IP was found and I'd log in using the browser. I can't find the network scan tool that locates them, normal ones don't find the IP like IP Scanner, or Angry IP.

Switches were installed and not configured they just worked as switches, so they weren't logged into all that often.

What is the model of these switches? 

Do you have any vlan configured?
It will be better if you have give information about network design and the connectivity this will be better to understand your issue :) 

if your switch has a console port, try to access it.
If your doing an IP scan and your switch is layer 2 and you didn't assign a management IP then your IP scanner will not find anything, unless your scanner work on the MAC address to find the supplier based on the first 24 bits of a mac address.
If you're saying that your switch work as a dummy switch no configuration, Vlan assigned, then try to reset it to it's default, login to the default IP and then change it to comply with your network subnet.

What's the model of switch?

Model: TP Link SG2424
I'm not onsite so I can't check MAC address or access via the console port.

from the link https://emulator.tp-link.com/TL-SG2424/Index.htm 

if you go to system information tab you can find MAC address of the switch for example

 in this case mac address of TPlink company begin with 00:0A:EB so you need to check in your network to which interface connected .

@Mohammad I'm working remote and can't physically get to the switch. Not sure why the IP address is not showing, obviously not turned on on the switch. Something else I'd like to do when/if I can get access.

Here's the link for TPNMS...
Download for TL-SG2424 | TP-Link (tp-link.com)