javascript is not handling line breaks in long strings, i am trying to generate a html script and i want to store it inside a single colon ‘ ‘ but it’s not working and that’s really weired!!

this is the code

i watched some videos and used AI but the issue remains unsolved and i tried to use double colon or triple colon but still same issue.
the only solution i have found was to split the lines individually like:
” +
” +
‘ ‘

but of course i am not gonna use this solution because it’s inefficient.