Joomla 4 is out, and it’s a beast, it’s going to chew up a lot of WordPress market share.
Mautic has a plugin for version 3 Mautic, by Mautic community - Joomla Extension Directory.
Any chance of getting this upgrade to version 4? Specifically, creating a contact from the Joomla user sign-up in Mautic is the attractive aspect of this module.
In some cases, only small changes need to be made to be Joomla 4 certified.