I don't think you do
You should first write down in plain English what it is you need to achieve, to clarify things for yourself.
e.g.
* when the user enters data in [field to observe]
* query the fabrik list
[listname]
* get the first record where [lookup field] = [field to observe's value]
* If a record is found then update the form with the map data field:
e.g. to insert the community build company value, into the quotes company field:
{"jaig1_comprofiler___company":"quotes_listed___company"}
I've altered your form so that it works, if you enter a client name as 'Greniewicki' - it will look up that and match against the community builder last name.
However! Really you should be doing look ups on id values, hence why in my previous post I said i had a user plugin (which stores the user ID) as my 'Field to observe' T
If selection was not appropriate, then you could hide the user element and set the autofill plugin to 'autofill on load': yes - to automatically map the users data into the form.