Is it possible to draw arrow from node to nothing?

How about this?

library(DiagrammeR)

mermaid("
     graph LR
        START[ ]-->A[Sample Text]
        A-->B
        B-->A 
        B-->STOP[ ]

        style START fill:#FFFFFF, stroke:#FFFFFF;
        style STOP  fill:#FFFFFF, stroke:#FFFFFF;
        ")

Output diagram is:

Something similar to another commentary but use opacity

library(DiagrammeR)
mermaid("
     graph LR
        START[ ]-->A[Sample Text]
        A-->B
        B-->A 
        B-->STOP[ ]

        style START fill-opacity:0, stroke-opacity:0;
        style STOP  fill-opacity:0, stroke-opacity:0;        ")