Web版試升級VUE3, 有個位置解決不了

[wilsonlintm]

            // 登录成功后会触发 SDK_READY 事件，该事件触发后，可正常使用 SDK 接口
            this.tim.on(this.TIM.EVENT.SDK_READY, this.onReadyStateUpdate, this)
            // SDK NOT READT
            this.tim.on(this.TIM.EVENT.SDK_NOT_READY, this.onReadyStateUpdate, this)
            // 被踢出
            this.tim.on(this.TIM.EVENT.KICKED_OUT, this.onKickOut)
            // SDK内部出错
            this.tim.on(this.TIM.EVENT.ERROR, this.onError)
            // 收到新消息
            this.tim.on(this.TIM.EVENT.MESSAGE_RECEIVED, this.onReceiveMessage)
            // 会话列表更新
            this.tim.on(this.TIM.EVENT.CONVERSATION_LIST_UPDATED, this.onUpdateConversationList)
            // 群组列表更新
            this.tim.on(this.TIM.EVENT.GROUP_LIST_UPDATED, this.onUpdateGroupList)
            // 网络监测
            this.tim.on(this.TIM.EVENT.NET_STATE_CHANGE, this.onNetStateChange)
            // 已读回执
            this.tim.on(this.TIM.EVENT.MESSAGE_READ_BY_PEER, this.onMessageReadByPeer)
            // 黑名单更新
            this.tim.on(this.TIM.EVENT.FRIEND_LIST_UPDATED, this.onFriendListUpdated)

            this.tim.on(this.TIM.EVENT.FRIEND_APPLICATION_LIST_UPDATED, this.onFriendApplicationListUpdated)

            this.tim.on(this.TIM.EVENT.FRIEND_GROUP_LIST_UPDATED, this.onFriendGroupListUpdated)

運行時出現ERROR Cannot read properties of undefined (reading 'on')

要如何自定ON?