Then for the marriage ceremony to be legally binding, it needs to be performed by someone who's authorized by the government to perform marriages.
Oh, OK, sure.
Once you have the license lots of people can officiate. I have some friends who got married by another friend. He sent off $20 and got some paper on the internet that gave him the legal status of minister, just so he could do their wedding.
I also attended a wedding once that was officiated by a Roman Catholic priest that was not a legal wedding. The groom was on major disability because he was quad. A legal marriage would cost them more than his fiance earned, they just couldn't afford it. So they got the religious wedding with no legal wedding.
Tom