Can't use smplayer as external player for Kodi

[ttthel]

Hello!
I tried to set up SMPlayer as an external player for Kodi (opensource multimedia center). I can't seem to make it work.
I edited the config file that allows that. It works fine with other players I tested (VLC, MPV).
When trying with SMPlayer it opens the SMplayer window, but doesn't play the video. It stays on a black screen with no possibility to press play.

OS: MXLinux 23.6 (Debian 12.13)
SMPlayer 25.6.0
SMPlayer engine: MPV
Kodi 20.1

SMPlayer log (I'm not sure how to share this properly):
[20:14:17:119] global_init [20:14:17:120] global_init: config file: '~/.config/smplayer/smplayer.ini' [20:14:17:120] Preferences::load [20:14:17:121] AssStyles::load [20:14:17:122] Preferences::load: config_version: 5, CURRENT_CONFIG_VERSION: 5 [20:14:17:122] Translator::loadCatalog: can't load "qt_C" from "/usr/share/smplayer/translations" [20:14:17:122] Translator::loadCatalog: can't load "qt_C" from "/usr/share/qt5/translations" [20:14:17:122] Translator::loadCatalog: can't load "qtbase_C" from "/usr/share/smplayer/translations" [20:14:17:123] Translator::loadCatalog: can't load "qtbase_C" from "/usr/share/qt5/translations" [20:14:17:123] Translator::loadCatalog: can't load "smplayer_C" from "/usr/share/smplayer/translations"

I have very minimal understanding of code and English is not my native language.

Thank you very much for any help!