Interesting question. Especially since they don’t list door handles separately from a door. But from previous experience I can tell you that the sealer is for bacterial protection, not mounting. It will have screws from the inside of the panel that mount the handle. Not knowing if you have a stainless or glass door, I can’t provide much more. Other than splitting the door gets into real warp-age problems and needs a jig to do. You may want to check with them.
Or if you have the part number for the handle, I may be able to find more on this.