C#/Javascript/Vue.js developer needed to run JS code over a webpage

I need to run a JS code (or whatever is needed) on a webpage to submit a captcha solution string. I already have a simple c# solution that uses selenium to open the page with the captcha and fills the captcha response text area with the string, but the submit part is missing; the webpage is not loading the solution.

The developer must understand which function is called in the webpage to submit that field and execute the correct JS code on the c# solution. I can share the solution. Thanks