How to get Refresh Token in Azure AD B2C

@Harjani, Ashish , To get an access token, you would need the scope as "offline_access" in your request, which I do see is present, but this call is going to the /authorize endpoint of B2C. Since you are using the Authorization-Code Grant flow of OAuth, hence in order to get the refresh-token, you would have to send a request to the /token endpoint of B2C, with the scope as "offline_access"

Sample Request:
POST https://{tenant}.b2clogin.com/{tenant}.onmicrosoft.com/{policy}/oauth2/v2.0/token HTTP/1.1
Content-Type: application/x-www-form-urlencoded
grant_type=authorization_code&client_id=90c0fe63-bcf2-44d5-8fb7-b8bbc0b29dc6&scope=90c0fe63-bcf2-44d5-8fb7-b8bbc0b29dc6 offline_access&code=AwABAAAAvPM1KaPlrEqdFSBzjqfTGBCmLdgfSTLEMPGYuNHSUYBrq...&redirect_uri=urn:ietf:wg:oauth:2.0:oob

You can find more details and reference on this here: https://learn.microsoft.com/en-us/azure/active-directory-b2c/authorization-code-flow

Hope this helps.

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