Add an server cron-job: Cloudways
If you are using Cloudways, the best way to set up a cron job is through the Cloudways cron
Create an external cron job on Cloudways
After logging in to Cloudways, go to Applications.
Select the application that Groundhogg is installed on.
Once in, click on Cron Job Management in the left-hand menu (the menu is titled Application Management)
With the Cron Job Management open, click on Add New Cron Job
With the pop-up open, under common settings select Every Minute (* * * * *)
Make sure the type is PHP. Enter the following into the Command setting.
Then click submit.
After it is added, you can use Groundhogg to check if the file is there, and if it isn't then wait a couple of minute for Varnish to update.
If wp-cron doesn't work by default on Groundhogg then adding it is very similar to adding gh-cron. Instead of selecting one of the common settings, it requires you to enter the 15 minutes.
If you try again in Groundhogg after a couple of minutes and it's not yet working, copy the link for it (that Groundhogg provides), and open it in a new window or tab. The file may be blank when you load it, but this tells Varnish and WordPress that there is a new cron job for it.
If you have the AWS SES integration installed you will have to create an additional cron job for it as well.
Enter the following into the Command setting
For the common setting, select Every Minute (* * * * *).
And then click submit.