How do I follow a recipe if my oven doesn't go as high as the recipe states? I want to bake bread. I found this recipe from Alex French Guy Cooking on YouTube.. His recipe says that the oven should be 250 degrees Celsius. My oven only goes to 220 degrees. I bought an oven thermometer to confirm and it taps out at 230 degrees. Do I just bake the bread for longer? If so how much longer?

UPDATE:

Here are the instructions from the comments section of the video. I did link the video in the original question but I see the link isn't very visible. (Just in case there is anything else you want to check)


  Ingredients you need : Flour, Water, Yeast, Salt and a Dutch Oven. Yes a dutch oven. It's the perfect way to bake your bread at home. Also, No need for sugar, modern yeast are powerful enough. No need for oil either.
  
  Instructions :
  40 grams of fresh yeast, 
  in 600 ml of tepid mineral water, or 15grams dry yeast. 
  In the bowl of the mixer drop 18g of salt.
  Then add 1 kg of bread flour and start slowly mixing.
  Add the water and the yeast. 
  
  As soon as everything is properly incorporated, set the speed to minimum, and knead the dough for 10 minutes.
  
  First proofing : Place the dough in an airtight container and let it proof in a warm and dark place for 1 - 2 hours.
  
  Then, Press down the dough, shape as seen in the video.
  Second proofing : Place the dough in an airtight container and let it proof in a warm and dark place for 30 minutes to 1 hour.
  
  Meanwhile, Heat dutch oven to 250°C or 480°F.
  
  Out of 2nd proofing, Sprinkle the dough ball with flour.
  Now using razor's blade, score the surface a few times.
  Squeeze on oven proof gloves, get the dutch oven out, place the dough ball inside. Back in the oven.
  
  I bake my bread at 250°C for 30 minutes, then at 230°C for another 30 minutes.
How much longer depends on the type of bread, the size and the shape of the loaf. The solution I suggest is to obtain a probe-type thermometer (like a meat thermometer) and use that to determine if your bread has baked for a sufficiet time. Many breads are completely baked at around 195F(90C) though I have seen a couple of recipes that call for 205F(96C)