When embedding web player cannot control the template to be used

[gpapp]

When embedding the player using the link generated from the player itself, the layout of the player cannot be controlled.

e.g.

<iframe title="Podlove Web Player: Zártosztály - Kedvenc maszkjaink" 
   src="https://cdn.podlove.org/web-player/5.x/share.html?config=https%3A%2F%2Fpodcast.itworks.hu%2Fwp-json%2Fpodlove-web-player%2Fshortcode%2Fconfig%2Fdefault%2Ftheme%2Fzartosztaly%2Fshow%2Fdefault&amp;episode=https%3A%2F%2Fpodcast.itworks.hu%2Fwp-json%2Fpodlove-web-player%2Fshortcode%2Fpublisher%2F912"
frameborder="0" 
scrolling="no" 
width="100%" 
height="270px"
tabindex="0">
</iframe>

Expected behavior

The config (default) defined in the template should be used.

Actual behavior

A simple template is used instead of the one defined in the config/default or the show/default parameters.

System information (see Podlove > Support menu)

Website                    https://podcast.itworks.hu
PHP Version                7.3.22
WordPress Version          5.5.1
WordPress Theme            myPortfolio v1.0.6
Active Plugins             
           - Akismet Anti-Spam v4.1.6
           - Download Free Images v1.3.0
           - Site Kit by Google v1.16.0
           - Jetpack by WordPress.com v8.9.1
           - Limit Login Attempts Reloaded v2.15.2
           - Podlove Podcast Publisher v3.0.4
           - Podlove Web Player v5.2.9
           - NextScripts: Social Networks Auto-Poster v4.3.18
           - Pexels: Free Stock Photos v1.2.2
WordPress Database Charset utf8
WordPress Database Collate 
Publisher Version          3.0.4
Web Player Version         player_v5
Twig Version               2.12.5
Monolog Version            1
open_basedir               /var/www/vhosts/itworks.hu/:/tmp/
curl Version               7.47.0
iconv                      available
simplexml                  ok
max_execution_time         30
upload_max_filesize        2M
memory_limit               256M
disable_classes            
disable_functions          eval, exec, passthru, shell_exec, system, proc_open, popen, curl_multi_exec, parse_ini_file, show_source
permalinks                 ok (/%postname%/)
podlove_permalinks         ok
podcast_settings           ok
web_player                 ok
podlove_cache              on
assets                     
  - mp3    audio/mpeg       https://podcast.itworks.hu/feed/mp3/
  - ogg    audio/ogg        https://podcast.itworks.hu/feed/ogg/
  - chapters.txttext/plain       no feed
cron                       ok
duplicate_guids            ok

0 errors
1 NOTICE (no dealbreaker, but should be fixed if possible): 
- The PHP setting "open_basedir" is not empty. This is incompatible with curl, a library required by Podlove Publisher. We have a workaround in place but it is preferred to fix the issue. Please ask your hoster to unset "open_basedir".