The current code is not consistent in style.
For example, single and double quotes coexist in the following file

https://github.com/twitterdev/twitter-api-typescript-sdk/blob/main/src/auth.ts#L4-L5

// Copyright 2021 Twitter, Inc.
// SPDX-License-Identifier: Apache-2.0

export * from '. /OAuth2User'.
export * from ". /OAuth2Bearer";

I recommend using a code formatter (such as Prettier) to improve the development experience going forward.
If you agree with this policy, I will submit a pull request.

Best regards.