There's evidence all over the place of Biden being against fracking. Words from his own mouth. Sometimes Joe's saying eliminate fracking, sometimes implying partial elimination, sometimes implying some phasing out to get rid of  fracking, even saying phasing out all oil drilling, not just fracking.  

And that's what Joe's telling his (environmental) supporters like AOC.  Over & over again. 

When Kamala flat out says Joe won't end fracking, she knows he's been all over the place on that issue.  This example you might call it Kamala obfuscating, trying to give the audience a wrong impression, hiding what Joe has been saying in so many venues.   Amounts in the final analysis, bottom line to conveying a false idea or just plain lying.

Here's Biden's own words, a 1 min video, with numerous examples.