How to output something In footer before body closing tag

Hi am trying to apply some custom js required for the block functionality which have some text come dynamically using lazy block fields. For example class name to initiate js and some option values etc. Actually creating a swiper slider block.

But I need to have this script not printed in the middle of page where the html output is printing, instead I want to print the script part to the last of the page before closing body tag. How it can be achieved ? This is required for script to not have conflict and also in case if it depends on some other script files which are added in footer.