Add signed APT repo using Puppet

I want to install Telegraf using Puppet 6, and I'm finding it really difficult to do so by using the apt module. I'm using the module so I can import the GPG key and add the corresponding source.

My manifest looks something like this:

  include apt  apt::key { 'influxdata':    id     => '05CE15085FC09D18E99EFB22684A14CF2582E0C5',    ensure => 'present',    source => 'https://repos.influxdata.com/influxdb.key',  }  apt::source { 'influxdata':    comment  => 'InfluxData repo to download Telegraf agent.',    location => 'https://repos.influxdata.com/debian',    release  => 'stable',    repos    => 'main',    key      => {'id'     => '05CE15085FC09D18E99EFB22684A14CF2582E0C5','source' => 'https://repos.influxdata.com/influxdb.key',    },  } ~> exec { "apt-update":    command =>  "/usr/bin/apt-get update"  }  package { 'telegraf':    ensure  => 'latest',  }

It seems to be working with no errors, but a quick cat /etc/apt/sources.list.d/influxdata.list shows that the repo is missing the signed-by part:

# This file is managed by Puppet. DO NOT EDIT.# InfluxData repo to download Telegraf agent.deb [   ] https://repos.influxdata.com/debian stable main

Ideally, it should be:

deb [signed-by=/etc/apt/trusted.gpg.d/influxdb.gpg] https://repos.influxdata.com/debian stable main

What am I missing?

TIA!