Sending Clipboard to URL

I am new to Keyboard Maestro and am trying to create a short macro which will send the contents of the clipboard to the Micro.blog app. I am using the apps URL Scheme microblog://post?text= in the form microblog://post?text=%SystemClipboard%

I notice as I enter the URL, the "Open URL" turns to orange. When I run the macro I get an invalid URL message.

If I just enter something like microblog://post?text=Hello%20World the macro works with the words, "Hello World" being sent to the app.

What would I need to do to send the contents of the clipboard to the app?

Hi @David19,
This post may be helpful to you.

Thank you @martin. That did indeed help and work.

David.