EXT JS UI Changes help wanted

Hi I need help with UI Changes, This is an OLD application developed in ext.js, I have to Create just a popup when submitting a button with a small condition. I will show these changes in meeting this is a very Small change if anyone has the experience, I do not have time to learn and complete this. so I would like to pay and complete this task. please feel Free to respond with your available time and Email or best Contact Details So I can schedule a meeting. if you are available now please let me know at the earliest time I have only option to connect zoom.