A Iron Broken Wing Butterfly is normally a credit and it is made by selling A Call and a Put at the same (or close) strike and then buying the wings OTM….The difference between a regular Butterfly and the Iron Bfly is that on the regular Bfly you sell either 2 Calls or 2 Puts and then buy a lower priced Call or Put and a higher priced Call or Put. Normally the higher priced option ends up ITM and becomes somewhat difficult to close.
To make it into a broke wing, you can do either shorten the spread on one side or sell more spreads on one side than the other.
Hope this helps.