The best way to seal it would be the 2 part urethane clear .( 2k )

You can get the aerosol cans that you activate the mixture of the 2 parts prior to application  -- this necessitates using all of the product in a very finite amount of time .

This page as example :, look for " 2K " : https://www.amazon.com/s?k=2+part+urethane+paint&ref=nb_sb_noss

Or ,

It can be airbrush applied with the mix readied only in the amount needed .

Example : https://www.splash-paints.com/product-page/2k-ultra-gloss-clear