Make Header Image Change Size According to Screen

I’m wondering if it is possible to make the header/top/hero image on each of my website’s pages responsive to different screen sizes. The images look great on my laptop, but are very small on my mobile phone. I have searched the forum for solutions, but cannot tell which ones would apply to my situation.My site is dougcrawfordwellness.com. Below is a picture of how it looks on my mobile phone. I would like the image to fill the screen from top to bottom. I can see from other sites that this is possible, but I just don’t know how to do it on my site.

For an example of what I am trying to accomplish, please have a look at this site: healingalternativestherapy.com.

Thank you for your assistance.

Hello,

I’ve already answered in this topic:

Please let’s continue there.

Kind Regards, Roman.
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