Alteração de accounts.json via API com Dart

account.json

[{"id":"ID002","name":"Ana","lastName":"Silva","balance":2413.9733340000002,"accountType":"Canjica"},{"id":"ID003","name":"Bruno","lastName":"Santos","balance":10213.02,"accountType":"Pudim"},{"id":"ID004","name":"Carla","lastName":"Oliveira","balance":500.0,"accountType":"Brigadeiro"},{"id":"ID005","name":"Daniel","lastName":"Ferreira","balance":180.0,"accountType":"Ambrosia"},{"id":"ID006","name":"Elisa","lastName":"Costa","balance":320.0,"accountType":"Pudim"},{"id":"ID007","name":"Fábio","lastName":"Pereira","balance":60.0,"accountType":"Ambrosia"},{"id":"ID008","name":"Gabriela","lastName":"Rodrigues","balance":200.0,"accountType":"Canjica"},{"id":"ID009","name":"Henrique","lastName":"Martins","balance":450.0,"accountType":"Pudim"},{"id":"ID010","name":"Isabela","lastName":"Almeida","balance":210.0,"accountType":"Brigadeiro"},{"id":"NEW001","name":"Allan","lastName":"Medeiros","balance":2100.0,"accountType":"Ambrosia"},{"id":"ID666","name":"Halley","lastName":"Commet","balance":1234.0,"accountType":"Ambrosia"},{"id":"5fcae745-ceb1-4cae-9e69-079f2d16ece8","name":"Allan","lastName":"Alberto","balance":2534.56,"accountType":"Ambrosia"},{"id":"1f4c8e6f-801d-44f9-bbe0-9723c9ae0a4b","name":"Makoby","lastName":"Medeiros","balance":123456.0,"accountType":"Pudim"},{"id":"85ad9059-0f54-485e-807c-a0d5ae908f13","name":"Daniel","lastName":"Marques","balance":1000.0,"accountType":"Canjica"},{"id":"4dea9934-7ca0-4321-b5a7-1d90992da28a","name":"Sebastian","lastName":"Vettel","balance":0.0,"accountType":"Ambrosia"},{"id":"e272c77c-f3f8-45f7-8b9a-253cafc530b5","name":"Alain","lastName":"Prost","balance":0.0,"accountType":"Pudim"},{"id":"dfe304c7-bf71-484f-8b12-9a5db4f7d49a","name":"Antonio","lastName":"Barros","balance":0.0,"accountType":"Canjica"},{"id":"8784b603-ae25-4b3f-a994-886e51f3d2fe","name":"Ceceu","lastName":"Barros","balance":0.0,"accountType":"Ambrosia"},{"id":"633e325e-4343-487c-b84f-5dfbddc99f29","name":"Satoro","lastName":"Nakagima","balance":0.0,"accountType":"Canjica"},{"id":"649d846b-dbf0-4e05-8d40-8c1a1645e674","name":"Kimmi","lastName":"Raikonen","balance":0.0,"accountType":"Pudim"},{"id":"2ce93298-8f3e-4a39-a4e0-70e1ba505556","name":"Nigel","lastName":"Mansel","balance":0.0,"accountType":"Ambrosia"},{"id":"6846bfa1-2afd-42a8-b4ab-297ac6e836c8","name":"a","lastName":"a","balance":0.0,"accountType":"Ambrosia"},{"id":"c10e7955-b8d2-486f-ae41-38e37622d726","name":"Ricarth","lastName":"Lima","balance":0.0,"accountType":"Ambrosia"}]

transactions.json

[{"id":"0","senderAccountId":"ID002","receiverAccountId":"ID002","date":"1971-04-30T08:18:04.000Z","amount":0.0,"taxes":0.0},{"id":"2025-04-10 09:08:19.671066","senderAccountId":"ID002","receiverAccountId":"ID003","date":"2025-04-10T09:08:19.673239","amount":50.0,"taxes":0.0},{"id":"2025-04-10 09:09:03.235551","senderAccountId":"ID002","receiverAccountId":"ID003","date":"2025-04-10T09:09:03.237321","amount":50.0,"taxes":0.0},{"id":"2025-04-10 09:10:04.228027","senderAccountId":"ID002","receiverAccountId":"ID003","date":"2025-04-10T09:10:04.229583","amount":5001.01,"taxes":16.503333},{"id":"2025-04-10 09:10:23.844151","senderAccountId":"ID002","receiverAccountId":"ID003","date":"2025-04-10T09:10:23.845817","amount":5001.01,"taxes":16.503333},{"id":"09a07e10-0ec4-470e-ac9f-031d9ae5ea16","senderAccountId":"ID002","receiverAccountId":"ID003","date":"2025-04-10T09:25:41.576244","amount":1.0,"taxes":0.0}]