Promises in SuiteScript 2.1 Server Scripts
SuiteScript 2.1 supports non-blocking asynchronous server-side promises expressed using the asnyc, await, and promise keywords. However, these keywords are only valid for a subset of modules: N/http, N/https, N/llm, N/query, N/search, and N/transaction. You will receive an error if you use the async, await, or promise keyword in a module other than the N/http, N/https, N/llm, N/query, N/search, or N/transaction modules. In other words, no other modules support the use of the async, await, and promise keywords in server scripts.