it's nice to have a real amp, to move air.... it's quite a different feel and vibe than using sims.
that said, if you don't have anything else to use, try the guy's suggestions about cloning and finding the right plug-in, and the right eq scheme, to come up with a way to blend clean and dirty to get grunt.
there's nothing to lose but time, and if you trip across something that sounds
really unique, it can become a 'signature' bass tone.
but ultimately, finding your tone with nothing but your bass, technique, and a good direct signal, is the ultimate.
this is the tone search.
the bass, the strings, your personal technique, the way you set your volume/tone/pickup heights, all that.....
it's not a random thing that just occurs.