step 1: do npm install
from the root of the folder
step 2: start the ganache cli by entering the command
ganache-cli -m 'candy maple cake sugar pudding cream honey rich smooth crumble sweet treat' --networkId 100 -a 10 --gasPrice 1 --gasLimit 8000000
step 3: do truffle migarte
step 4: do npm start
will start the node js api
step 5: use postman to hit the api's on
http://localhost:8081/api/purchase http://localhost:8081/api/received http://localhost:8081/api/cancel