Can I use Firefly generated photographic images as a reference when illustrating a brand icon?

Hi,

I’ve been asked by my client to create a brand icon for them to use on a product.

Can I use Firefly to generate a photographic reference - that I create a derivative artwork from (ie taking it from a photo to an illustration I will draw) - that can then be used as a brand trademark icon?

EG, client wants an icon of an elephant. I use Firefly to generate references of elephants (photographic) that I then draw by hand, before scanning the sketch and further refining it as a vector - with the end product being used as a trademark.

Hope that’s clear.

Many thanks!