Grocery check out create a step$-$by$-$step white box testing example

A customer needs to send grocery to a friend who lives in another state. They're going to use mobile grocery app.

Step $1$: identify the feature, component, program to be tested "keep narrow focus"

Step $2$ : plot all possible paths in a flow graph like example shown below:

Step$3$: identify all possible path from flowgraph

Step$4$: write test case to cover eevry single path on flowgraph