The detail object of the event contains the following structure:
{ membership: { id:13579, planId:151, publicPlanId:"abc123", name:"Super plan",// type [ 'free' | 'one_time_payment' | 'subscription' | 'multi_payment' ] type:"subscription", createdAt:"2021-03-24T15:31:55Z", status:"active",// expiresOn [ ISO-8601 | udnefined ] indicate that a **non-subscription** is// due to expire at a specific date. expiresOn:"2022-03-24T15:31:55Z"// cancelsOn [ ISO-8601 | undefined ] indicates that a recurring// **subscription** is being cancelled at the billing period end cancelsOn:"2022-03-24T15:31:55Z",// billingPeriodEnd [ ISO-8601 | udnefined ] indicates that when the next charge// on a **subscription or non-completed multi_payment** is due. billingPeriodEnd:"2021-06-24T15:31:55Z" paymentFailure:true, welcomeUrl:"/welcome-to-super-plan", contentUrl:"/super-plan-content" }, order: { id:"string", subTotal:12.35, subTotalCents:1235, grandTotal:12.35, grandTotalCents:1235 }, member: { id:678910, name:'John Doe', firstName:'John', lastName:'Doe', email:'john@doe.com', stripeCustomerId:'cus_xxxxxxxxxxxxxx', }}