You can back feed your generator in the dryer outlet after you switch off the main breaker. You might get an electric shock if you don’t switch it off before the backfeed or even destroy the generator. To make the connect, you can either use 12 or 14-gauge extension cord.
However, it isn’t allowed in all states in the United States, so you will have to check with your local repair shop if you can do it. If the network fails, you will have to call a repairman. To avoid the chances of it happening, you can instead install an automatic transfer switch.