Extracting webcam URL with RegEx

I am trying to set up a button at my parents house to let them watch a webcam feed on a Chromecast. The URL for the feed has a token that changes so I can’t just copy and paste the address into a rule, but enough of it stays the same for me to find it with a regular expression. I was looking to extract the URL for a webcam from a webpage to pass along to the Chromecast binding when a button on HabPanel is pressed.

The address takes the form https://e1-na3.angelcam.com/m6-na3/2663/playlist.m3u8?token=eyJhbGlhcyI6ICIyNjYzIiwgInRpbWUiOiAxNTIzNTgzOTY5NzE3MjQ5LCAidGltZW91dCI6IDM2MDB9.6dfd9027064d2183872351ceec1b9261f9ef7281caca29fa35ead3a3f53a8bf3

The RegEx e1-na.*?(?=’) works fine on https://regex101.com/ when I paste in the HTML from the address. However RegEx doesn’t extract any data instead NULL gets written to the CanalCam_URL item.
As a test I wrote the contents of the urltemp variable to a string variable and it is dumping the HTML to it.
I also set logging to TRACE on RegEx (org.eclipse.smarthome.transform.regex) and it says

' by the function 'e1-na.*?(?=\')'
12-Apr-2018 20:41:34.525 [DEBUG] [ransform.regex.internal.RegExTransformationService] - the given regex '^e1-na.*?(?=\')$' doesn't match the given content '


' -> couldn't compute transformation

So it looks like it is reading the RegEx .(e1-na.?)’ as ^e1-na.?(?=’)$. I’m not sure why it is not reading it correctly.

Here is the rule runs when the button in HabPanel is pressed.

rule "Canal Cam URL Update"
        Item CanalCam_Play_Switch received command ON
        var String url = "https://v.angelcam.com/iframe?v=vbolkpk8y8&autoplay=1"
        var String urltemp = sendHttpGetRequest(url)
        var canalcamurl = transform("REGEX", ".(e1-na.*?)'", urltemp.toString)
        CanalCam_URL.postUpdate("https://" + canalcamurl.toString)

Try this binding that I have started to write very recently. It will fetch the video and snapshot URLs and offer them to you in a String item, you can then use them in openhab from the string. I found my camera reported a different URL when asked via ONVIF when compared to normal http access, so there is a chance this may be a work around for you.