I am so sorry for not explaining it concisely.
Basically, my users.html has a script that reads the window URL and gets the last string after a slash.
For example: webpage.com/users/theusername
The script will read the theusername. Then, it will fetch theusename's information from the server using AJAX and plug the data in the DOM.
I have tried your suggestion but it seems like Netlify understands that theusername is another page and returns 404.
Anyway, thank you so much for your help.