rjpp on "How to make an HTML image responsive"

My URL is: http://info.tradiaglobal.es/

Hi everyone.

I have this website with a template and adapting it's slider options with an HTML image 980 X 400 instead of inserting an image slider to the theme's options since I have a contact form displaying on the slider options. The theme allows me to switch back and forth to responsive options, but when I set up the responsiveness, this is what happens:

image.png

My question is, is there a way to edit an HTML image for responsiveness?