I want to integrate with Miscrosoft Outlook. I am able to login with MSAL.js and get an access token, but I am not able to get a refresh token. Is there a way to do it?
I'll assume that since you're using the MSAL.js (https://github.com/AzureAD/microsoft-authentication-library-for-js) that you're using implicit flow for authentication and authorization.
Implicit flow doesn't support refresh tokens, but you can request a new token silently. This is done similarly to how you request the token (id or access) in the first place. Unfortunately, I haven't found that MSAL.js does this transparently and I've needed to detect expired tokens and request the new tokens in my code. You can read more about refreshing tokens here.
Alternatively, if what you're implementing allows you to use one of the other MSAL libraries (for example, the .Net one) then you can use one of the other OAuth flows that explicitly support refresh tokens.
来源：https://stackoverflow.com/questions/44111753/is-it-possible-to-use-msal-js-to-get-refresh-token