In order to extract a good amount of liquid safely, I chop the peppers fine, salt and place in a covered container in the fridge overnight.
The peppers should be fully covered in brine before you start fermenting at 65-70 degrees, (you don't want to be encouraging something like Listeria before the lacto bacteria kick-in).
Pack the peppers in a jar (working the peppers to extract maximum liquid)), all the way to the top to exclude air (if there's not enough natural liquid, top-off with brine) then top the jar with a weighted lid. Set in a jar to catch any overflow and cover to exclude light. I also use a 4 oz. Ball jelly jar as a weight (fits into the top of a wide mouth canning jar), to weight down the peppers or kraut or whatever, it'll also catch any expansion.
As far as excluding air, there's the good, better and best approach.
Good, is ensuring that what you're fermenting is well below the liquid (many people still ferment in open containers like that and have for ages.)
Better, is bringing the liquid all the way to the top of the container and using the weighted lid (this is the method that I use most of the time, and have for years), again fully covered with brine.
Best, is to use an airlock, with the peppers, etc. fully covered with brine. ( I still use this method sometimes)
when you say bringing liquid to the top of the container do you mean instead of the salt layer in between the peppers, making salt brine instead?