I tried to build a foam gun and FAILED

I tried to build myself a foam gun that attaches to a regular garden hose like the Gilmour Foammaster 2.

I assemble the kit from ACE Hardware, comprises of 2 things; 1) solution bucket 2) hose gun.

2 parts of the kit


Once assemble it look this.


However it did not produce any foam, just water. On their website it showed foam!

I have a hunch why it's not working but does anyone know why? More importantly how to make it work?

Thanks in a million.

I went to Osren last week and asked about the Foam Gun that connects to a regular garden hose. They don't have it.