Cannot get ssl switch to activate

Anyone out there who can help? Designed and built website dramatime.co.uk and when we attempted to switch on the ssl it wouldn’t activate. Went through troubleshooter and have changed out the http: for https: in the code (access through ctrl+U). but it keeps reverting back. Copied the site to try this first and it worked on the copy. What am I doing wrong please? Losing will to live. Thanks

And please feel free to give me an idiots guide.

Hi,
Check out this article about HTTPS and ssl.

ive seen this article before. it does not clarify what i need to do.