Hi! I have an error when clicking the "Insert" button, I get this:
These are my blocks and layout:
I think you are trying to change spacing to %20.
Make sure that there is a space in the marked area of the below picture.
If you don't type anything in that part, each letter will be inserted like a picture of the question.
The Web component has a block to handle this, used mostly for the back part of the URL around the variable data.
UriEncode( text )
Encodes the given text value so that it can be used in a URL.
(from http://ai2.appinventor.mit.edu/reference/components/connectivity.html#Web)