When creating a relationship between to elements e.g. with Uses(FCMHandler, "Sends out notifications via", "HTTP") the technology (here "HTTP") is completely ignored and not being rendered to the arrow.

C4 usually contains those in "[, ]", like "[HTTP]", see https://static.structurizr.com/workspace/76749/diagrams/Containers.png
When creating a relationship between to elements e.g. with
Uses(FCMHandler, "Sends out notifications via", "HTTP")the technology (here "HTTP") is completely ignored and not being rendered to the arrow.C4 usually contains those in "[, ]", like "[HTTP]", see https://static.structurizr.com/workspace/76749/diagrams/Containers.png