How can I change header images in categories and remove the “category”

Dear Frank,

I have just checked your URL
https://fitgearessentials.com/category/cardio-machines/

let me answer each query separately,

I am trying to change the header image in each category, but I can’t do it.
You are not using this plugin on provided URL. That is default header settings, not from this plugin. Category based banner image feature is not available in FREE version, please check on settings page with golden color links.

I cannot find an option to either remove the header image or add a new one.
You might be seeing some other page, please check the settings page, there is an option to clear the previous image.

I installed the “WP header image” plugin, but it let me only choose some default images, and I couldn’t find a way to add new ones.
Each accordion section is having a placeholder where you can click and upload a new image through image library, maybe you are missing that part?

I am also trying to remove the “Category” text from the header image, as well as the “test 6” text, which is a title of one of my test posts.
As mentioned above, you are not using this plugin on category page. Free version will not change anything on category pages.

I have deleted my cache and also my browser history and cookies, but it didn’t help.
You can reach me through demo website so i can help you in a better way.