By assignment, all secret keys must be obtained from environment variables. All environment variables are string variables. The program developer can also check the length of the key when verifying the correctness of the key. The length for the int type is not defined. There is no reason to use int type for TELEGRAM_CHAT_ID key.
Yandex API requires int type as input. The API does not work with the float type. The developer can convert function arguments to int type in the program code. In this case the tests do not pass.