我正在为Hyperledger Fabric智能合约创建自定义API端点，并且正在使用邮递员进行测试。帖子状态为200，但抛出并且无法读取commitTransaction（）函数的错误如何解决此错误
终端错误：
TypeError: Cannot read property 'submitTransaction' of undefined
at Object.exports.invoke(/home/hlf/dpt_old/webapp/api/network.js:133:50)
at router.post (/home/hlf/dpt_old/web-app/api/routes/members.js:32:34)at <anonymous>at process._tickCallback(internal/process/next_tick.js:188:7)
POST /members/ 200 88.465 ms - 386
邮递员错误：
"message": "Cannot read property 'submitTransaction' of undefined",
"stack": "TypeError: Cannot read property 'submitTransaction' of undefined\n at Object.exports.invoke (/home/hlf/dpt_old/web-app/api/network.js:133:50)\n at router.post (/home/hlf/dpt_old/web-app/api/routes/members.js:32:34)\n at <anonymous>\n at process._tickCallback (internal/process/next_tick.js:188:7)"