Do you mean how do you get the fingering of the chord to display when you hover the mouse over it once the tab is added to the site?

If that's what you mean, just by submitting a plain text file with lyrics on one line and the chords on the line above is enough - the site automatically sorts the rest out for you.
Gibson LP Traditional, LP GT, LP Studio, SG Standard x2
Barber Tone Press > EHX Worm >TC Polytune > MXR Custom Badass 78 > EXH Glove > EHX East River Drive > Zoom G3 > TC Spark Mini Booster
Laney VC30
Marshall TSL602
Jet City JCA22H
My SoundCloud