No! Many times, newly installed skylights are improperly installed which leads to cracks and gaps around them. Sealants can help up to some extent. However, if your newly installed skylight looks like the one in the above image, it needs to be re-lifted and with a proper flashing detail around the perimeter of your frame. As it seems to be installed sideways.
To handle this job it’s best to hire a roofing contractor.