You do not receive messages
In order to send messages, the extension starts a background process, which runs continuously. It listens for the new registered events and sends notifications.
This background process is launched by cron, and it requires the function
execto be enabled to run it.
However, you won't be able to receive the messages if this function is disabled. So, in that case you can ask your server admin to enable the PHP
execfunction or just add the cron job below to the server crontab:
* * * * * <path to php binary> <magento install dir>/bin/magento mirasvit:message-queue:subscribe > /dev/null 2>&1