Thanks for the quick reply. It turns out to be how $ua->credentials($user, $pwd) as encoding the credentials. When I delete the credentials line and use $url="https://$user:$pwd\@api.mysite.com/2022-01-08/enrich/upload" instead, it works. So this is what I ended up with.

#!/usr/bin/perl

use warnings;
use strict;
use LWP::UserAgent;
use Data::Dumper;

my $ua = LWP::UserAgent->new(); 

my $user = "any_string";
my $pwd = "{secure_token}";

my $url = "https://$user:$pwd\@api.mysite.com/2022-01-08/enrich/upload
+";
my $data = 'testme@mysite.com';
my $webhook = "http://mywebhook.com/";

my $content_type = "form-data";

my $response = $ua->post($url, Content_Type => $content_type, Content 
+=> [data => $data, webhook => $webhook] );

my $content = $response->as_string();

print ($content);
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