#!perl
use strict;
use warnings;

use LWP::UserAgent;

my $ua = LWP::UserAgent->new( 'send_te' => '0' );
my $r  = HTTP::Request->new(
    'POST' => 'https://[URL]/[ENDPOINT]/item?key=%5BKEY%5D&token=%5BTOKEN%5D',
    [
        'Accept'         => '*/*',
        'User-Agent'     => 'curl/7.55.1',
        'Content-Length' => '25',
        'Content-Type'   => 'application/json'
    ],
    "{\x22value\x22: {\x22text\x22: \x2238\x22}}"
);
my $res = $ua->request( $r, );



__END__

Created from curl command line
--request  'https://[URL]/[ENDPOINT]/item?key=[KEY]&token=[TOKEN]' --header 'Content-Type: application/json' --data '{"value": {"text": "38"}}'