I haven't found properly way how to decode base64URL to base64 format in swift. 

According to [base64url to base64](http://kjur.github.io/jsjws/tool_b64udec.html) `hJQWHABDBjoPHorYF5xghQ`(base64URL) should be `hJQWHABDBjoPHorYF5xghQ==`(base64). Here could be more differences.

There are no solutions on stackoverflow.