Cron via http

And the possibility of a campaign to send manually without use cron? Instead of collecting date, immediately send.
Everything in mailwizz relies heavily on the use of cron job, you can't do many things without these.
However, if you have a developer, you can simply create a controller and in it to put the contents of the apps/console/commands/SendCampaignsCommand.php file then access it via url.
I am not sure if it will work, but you can try it.