Import enum as a type containing the values

interfaces.d.ts

export * as SSOProvider from "./sso-providers.js";

export type SSOProvider = typeof SSOProvider[keyof typeof SSOProvider];

sso-providers.ts

export const AMAZON = 'amazon';
export const APPLE = 'apple';
export const FACEBOOK = 'facebook';
export const GOOGLE = 'google';
export const GOOGLE_JWT = 'google-jwt';