Problem with GF forms fields mapping for Velocify

Hi,
I was looking for a proper guidance or documentation of integrating GF Forms with Velocify using Forms:3rd Party integration. But unable to find right direction and ended up here knocking you whoever has good experience on this to share knowledge. 🙂

*** Service ***
Array
(
[name] => Contact US
[url] => https://secure.velocify.com/Import.aspx?Provider=....../thank-you.php
[forms] => Array
(
[0] => gf_33
)

[success] =>
[failure] =>
[timeout] =>
[hook] => true
[dynamic-format] => %s = %s;
[mapping] => Array
(
[0] => Array
(
[val] => 1
[lbl] => First Name
[src] => [input_3_3]
[3rd] => fname
)

[1] => Array
(
[val] => 1
[lbl] => Last Name
[src] => [input_3_6]
[3rd] => lname
)

[2] => Array
(
[val] => 1
[lbl] => Email
[src] => [input_2]
[3rd] => email
)

[3] => Array
(
[val] => 1
[lbl] => Message
[src] => [input_4]
[3rd] => message
)

)

[separator] => ,
)

*** Post (Form) ***
http://www............com/contacts/
Array
(
[input_3_3] => Test
[input_3_6] => Testy
[input_2] => user@domain.com
[input_2_2] => user@domain.com
[input_4] => Dummy Dummy Dummy Dummy Dummy Dummy Dummy
[input_5] =>
[gform_ajax] => form_id=33&title=&description=&tabindex=1
[is_submit_33] => 1
[gform_submit] => 33
[gform_unique_id] =>
[state_33] => WyJbXSIsImFhOTk0MTU0MzM0YWM2YjNhYWZlMGExZmZmODEwZTkxIl0=
[gform_target_page_number_33] => 0
[gform_source_page_number_33] => 1
[gform_field_values] =>
)

*** Post (to Service) ***
Array
(
[timeout] => 10
[body] => Array
(
[fname] => [input_3_3]
[lname] => [input_3_6]
[email] => [input_2]
[message] => [input_4]
)

)

*** Response ***
Array
(
[headers] => Array
(
[date] => Wed, 07 Jan 2015 18:22:13 GMT
[server] => Apache
[connection] => close
[content-type] => text/html
)

I tried to map GF fields by using input_3_3 or [input_3_3]. Nothing worked.

Let me know what I am missing here.

https://wordpress.org/plugins/forms-3rdparty-integration/