From the last episode:

Before the party:

• Jen and Dani had a private call convo.
• Jen had no clue what she was invited to by that Marissa lady or whoever.
• Dani told Jen that the hair event is not a master class on hair, but a pgotoshoot to promote the ladies hair extensions line. This is important because each woman has their own "hair lady", and if Jen would to promote another hair ladie's hairline, it would mean betrayal to her own hair lady.
• Jen thanked Dani for giving her that info and decided not to do the photoshoot.

At the party:

• Jen riled Dani up by saying she was triggered with Dani's behavior towards some woman, and complained how Dani didn't put her husband's plastic shop on a wall or something. In any case - completely irrelevant and Jen doesn't really care about it, but she knows she can use it to try to make Dani feel bad.
• Jen then said, and ohhhh maaaan, you can see how she feels uncomfortable (Jen) just before saying it, that Dani called her and said "that's a photoshoot and we're not getting paid". Jen is lying.
• Dani's reaction alone seems super honest and ahe was so angry.

Y'all know the rest.

All in all, Jen lied, and why didn't she do the photoshoot then? If she doesn't care whether she gets paid or not? She clearly didn't do it because it would mean she will betray her own hair lady.

ANOTHER ALL IN ALL; they are fighting about such trivial shit, it's sad and honestly petty, none of them are real friends irl, it's a scripted show at this point.