Auto submit web form and extract the data in a text file

I am looking for a solution to automate the form submission and get the result in a text file or to pass it on to next form.

Let me tell you what exactly I am looking for.

1. I have list of 800 links in a text file, I want to pass them on to a web form one after another to get direct video link. e.g. submitting URL to 9xbuddy website to get the direct link of the video with "High" quality.
2. For all the 800 links, I want to automatically extract direct video links and save it to a text file. Additionally, pass on the links to another web form. e.g. thoaimedia.com to save it to my youtube account automatically.

Can anyone please suggest a way or an example to do the same. I am on MacOS Sierra 10.12.

Thanks in advance.