I did try with LWP but I get the same perplexing problem!!! I'm trying to go to https://taxfoundation.org/2018-tax-reform-calculator/ and use their tax calculator from Perl. I am TOTALLY bamboozakled on why this is failing! 
#!/usr/bin/perl

use strict;
use warnings;

use HTTP::Request::Common qw( POST );
use LWP::UserAgent;

my $ua = LWP::UserAgent->new;
    
my $req = POST 'https://tax-calculator-api.taxfoundation.org/taxcalc/t
+cja_submit',
    [
        Host              => 'tax-calculator-api.taxfoundation.org',
        Connection        => 'keep-alive',
        Origin            => 'https://taxfoundation.org',
        'User-Agent'      => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64
+) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/
+537.36',
        'content-type'    => 'application/json',
        Accept            => '*/*',
        Referer           => 'https://taxfoundation.org/2018-tax-refor
+m-calculator/',
        'Accept-Encoding' => 'gzip, deflate, br',
        'Accept-Language' => 'en-US,en;q=0.9',
        Content           => [
            '401k_contributions'    => 0,
            business_income         => 0,
            charity_contributions   => 0,
            child_dep               => 2,
            filing_status           => 2,
            interest_paid           => 0,
            medical_expenses        => 0,
            nonchild_dep            => 0,
            ordinary_income1        => 150000,
            ordinary_income2        => 0,
            other_itemized          => 0,
            qualified_income        => 0,
            sl_income_tax           => 0,
            sl_property_tax         => 0,
            ss_income               => 0,
        ],
    ];

print $ua->request($req)->as_string;

[download]

In reply to Re^2: Runs from Command Line but NOT from Perl by Anonymous Monk
in thread Runs from Command Line but NOT from Perl by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.