Creating/Updating/Patching Interactions
These interactions (as well as transaction/batch and many operations) use one of the entity-enclosing HTTP methods: POST, PUT, or PATCH. When one of these is selected, you also need to specify a request payload/body. You can choose Use Template to enter a direct text template, or Use Builder to use the FHIR Resource Builder to create a payload for you.
When using the Builder mode, the resource being built is automatically selected for you, depending on the resource and/or interaction you've chosen.