help iam new to json

[scotty533]

can somebody tell me how to create this please {   "SubscriptionId": "7620A519",   "MainData": [     {       "TransactionAgreement": {         "TransactionSource": {           "Institution": "Test Bank",           "AccountHolder": "John Doe",         },         "Reference": "EXT-AAA-0000001"       },       "TransactionsToSchedule": [         {           "ScheduledDate": "2021-03-11T00:00:00+10:00",           "Reference": "AAAAA-BBB-CCCCC-DDD-EEEEE"         }       ]     }   ] }