NTLM security in HTTP request

Hi everyone:

I'll provide some context first:

At work we had some API calls to SharePoint 2010 that read and wrote stuff items to a sharepoint list.

This was achieved suing webread and webwrite.

But our company is moving our lists to SharePoint 2019.

I was able to adapt all the GET calls to work with the new api (before it used _vti_bin), but when I started adapting the POST calls, I started getting the 403 FORBIDDEN status.

The IT department informed me that I should use a "Transport" security mode, and later on they said that the correct option should be "NTLM".

I looked at these resources:

HTTP request message - MATLAB (mathworks.com)

Using matlab.net.http.RequestMessage.Send with NTLM authentication - MATLAB Answers - MATLAB Central (mathworks.com)

Server Authentication - MATLAB & Simulink (mathworks.com)

But I keep getting 403.

Now the actual question(s) is(are):

What approach is recommended to acheive this? Does webwrite support NTLM? If so how is this case configured?

Thank you very much for your time!

Andrés.