“I am trying to figure out if it’s already been fused, how do I do a bubble squeeze when the edges are already sealed? “
As you have guessed, if the edges are sealed, no amount of bubble squeezing will do the job you want. It has to be done on the first fusing. The bubbles in the fused piece are there for life, unless you want to drill them out.
The bubble squeeze is in the range of 650-677C. This determined both by the glass and personal preference. You can do a soak at the temperature you choose, or you can take an hour to do the 25C up to the desired temp, with or without a soak.