ESP8266 Wi-Fi connection setup

Hello,
I'm using Arduino IDE GK kit w/ FW v11.0.1 along with Wi-Fi board for almost 10 years. I bought the WiFi board from a guy who set the SSID and password needed for its internet connectivity. He also set the radmon.org feed from my station. The problem is that I'd like to change the SSID and password, but IDK how to. Also, I don't want to break something and stop feeding radmon.org from my station. I'm not an IT, but if someone explains to me step-by-step how to do it, I could try. Is there a web terminal or something where I can connect that ESP8266 board and change these things? It's interesting to me also how to program it to upload to radmon.org, so one day I could fix it, if my crappy hands do something wrong.

Regards,
Emo

is this the software used ?
https://sites.google.com/site/diygeigercounter/home/gk-radmon?authuser=0

there is a link on that page to a user guide to configure it :
https://www.dropbox.com/s/frou0vsbpkomuel/GK%20Radmon%20Build%20and%20User%20Guide%20v2.2.pdf?dl=1
But probably you have an older version and much could have been changed
It seems possible to boot into "AP Config Mode" and then use your phone's browser to configure the device .

I don't think that's the software used, but many thanks for the second link provided. I downloaded the documentation from the link, and when I moved it to the folder with the other GK documentation, I saw that I already had some previous documentation for the hardware version of the WiFi kit I have. So I'll try to set a new SSID and Password next week. In the documentation I have, I can't see any options for AP, or I'm missing something. Maybe for changing it using my software version, I can use only the FTDI connector. Could you please check and tell me if I'm correct?

https://drive.google.com/uc?export=download&id=1Wks9VW-h_M6-mhb8uyzMSq3ArvgYrWW9

Thanks!

Ouch , that's going to be a challenge.
From reading the doc there is no web interface to configure the device.
Instead the info is hard coded in the software.
You will need to edit the file : credentials.h with all the required info needed to send data to the servers and your wifi credentials, and giger counter settings.
You could check if you can find a "credentials.h" file somewhere with the wifi settings you currently use already filled in. That would mean you have the source code that is already set up with your personal settings to start with. would make things easier.

Then compile everything.
Then upload the compiled software to the board.

Given the age of that software, that is not going to be a 1 shot process.
highly likely you will run in to issues with old libraries, drivers , and IDE. that will need to be addressed. (maybe use an old version of the arduino ide)

And if it fails to connect or upload to the board it's going to be all but impossible for anyone not having the same setup to help with that step.

Hmmmm my GK WiFi board is totally the same like this one here:

https://sites.google.com/site/diygeigercounter/networkkit

At the bottom of the page is written: "The Build Instructions for the current v1.5 board with v2.0 software are here." And the files from the hyperlink are these:

https://drive.google.com/drive/folders/1tnz2gONcVUhwagSvIU7VtlaZBXMnuSv6?usp=drive_link

In the main folder is software v2.0. In the folder "Previous Versions," you'll find v1.6 and v1.7. So, I guess one of these SW versions is for my Wi-Fi board (which, as I said, is pretty the same as the one from the link above). Now the question is how to know which one is my version? All of them have a Credentials tab when open in Arduino, so does that mean I could use any of them, since they were made for the same board? And as I said, I'm not an engineer, I'm a physician, so better to ask - I should use FTDI-USB adapter to load the sketch with credentials changed to my WiFi board, correct? Should I leave the quotation mark or delete it when entering new credentials? Sorry, too many questions, but I got a bit excited when I found that folder

Version 2.0 is what i would go for.
Yes according to the instructions you have to use the FTDI-USB adaptor .
But first you need to compile the configured software.
Leave the quotation marks around the strings, otherwise you will get errors.
I would try compiling without uploading first to see if that works.
next is trying to upload the compiled software.