FIX `A computed property name in a type literal must refer to an expression whose type is a literal type or a 'unique symbol' type.ts(1170)`

unique_symbol.ts

type PlanName = 'free' | 'starter' | 'growth' | 'plus'
type PlanDuration = 'monthly' | 'annually'
type BillingPlanEvent = `billing_${PlanName}_${PlanDuration}_click`

type GuidacneStep = 1 | 2 | 3
type GuidanceEvent = `guidance_step${GuidacneStep}_next_click`

// A computed property name in a type literal must refer to an expression whose type is a literal type or a 'unique symbol' type.ts(1170)
// Fix?

export type UserEventPayload = {
  home_tasks_click: {}
  home_tasks_toggle: {}

  billing_enter: {}
  billing_leave: {}

apply_flash_sale: {
    apply: 'on' | 'off'
  }
  billing_demo_click: {}
  billing_customer_support_click: {}
} & {
  // 1
  [K in BillingPlanEvent]: {}
} & {
  // 2
  [K in GuidanceEvent]: {}
}

export type UserEventKey<E> = E extends keyof UserEventPayload ? E : never
export type UserEventProperties<E extends keyof UserEventPayload> =
  UserEventPayload[E]

mapped type./