Well since you asked so "fuckin" nicely /s

    if( condition ){
      import('../../../hugeFuckingLibraryThatTakesSeveralSecondsToLoadUponColdStart').then( x => {
          //do something with x
      })
    }

> ...nerd bullshit...

I hate to break it to you darling, but programming is nerd bullshit.

edit: alternate that might too much "nerd bullshit", but uses async/await if the surrounding code is an async function:

     async function doSomeStuff()
    {
        if( condition ){
          const x = await import('../../../hugeFuckingLibraryThatTakesSeveralSecondsToLoadUponColdStart');
          //do something with x
        }
    }