i don't have this option in profit miner
Apologizes, I can see that Claymore miner has this option but Phoenix Miner does not.
Anyway, Phoenix Miner supports only "Blake2s" as dual mining.
You can untick Blake2s algorithm from Algorithms in options.
That should do the trick.
With the recent development release 7.0.7, the "Dual mode" setting should be visible in the Properties dialog for PhoenixMiner in the same way as it's available for Claymore Ethereum miner.