There are two ways to install the Reminder App on your Rocket.Chat server.
If your Rocket.Chat server is connected to Rocket.Chat's Cloud, then you'd have access to the marketplace from where you can install the app. Please follow the following link:
{% content-ref url="install-from-marketplace-recommended.md" %} install-from-marketplace-recommended.md {% endcontent-ref %}
But, if you don't have a cloud account, then you can manually install the app on your server using the following guide
{% content-ref url="manual-installation.md" %} manual-installation.md {% endcontent-ref %}