No you don't. The RØDECaster Pro II and RØDECaster Duo features ultra-high-gain preamps with 76dB of gain on tap, which is plenty of gain for any microphone, even low output dynamic mics. And the noise floor of the preamps is so low that using a lifter or line booster will actually introduce noise to your signal, so we highly recommend not using one.
For more information about RØDECaster Pro II & RØDECaster Duo, please see our RØDECaster Pro II User Guide and RØDECaster Duo User Guide