MereChurch comes with a Planning Center integration out of the box. However, accessing this feature requires a little bit of extra setup work. Currently, an integration is considered custom work and requires an upfront payment as well as an increased monthly cost of $49/mo.
You can reach out to [email protected] for more information setting up your MereChurch website to pull data directly from Planning Center events. Once setup is complete, you can enable this setting in Settings > Events > 'Sync Event Calendar with Planning Center.'