get webhook signing secret, regenerating if requested

Request

• Base URL
  https://api.jambonz.cloud/v1
• Auth
  HTTP bearer
• TypeScript
  https://skmtc.dev/jambonz/apis/jambonz-api/docs/Accounts/:AccountSid/WebhookSecret/get.ts

  A function with typed inputs. Its response is checked against the schema.