I am new to regular expressions and am having trouble extracting the data between "[" and "]" using the 'Search using Regular Expression' action in the following variable, any help would be greatly appreciated:
Your original regex is a positive lookbehind for the opening bracket, then anything (which finds the URL), then a positive lookahead for the closing bracket. The lookbehind and lookahead don't capture (they are just requirements), so that's why the brackets aren't included in the found text.