You can transfer funds between a legacy address beginning with 1 and a SegWit address beginning with 3 in imToken, but not to a native SegWit address beginning with bc1, which is as yet not supported by imToken.
If you want to transfer BTC to a native SegWit address, please first fund your tokens to an exchange and then transfer them from the exchange to the address beginning with bc1.
Disclaimer: The token trading service is provided by a third party, and this article does not constitute any investment advice.