What tools are currently relevant for modeling business processes?

Question

UML

The essence of the problem is this: there is a big project, you need to model business processes, they are long and branched)
Ideally, so that you can sit down with the customer and carefully design each process, and then make changes if something changes along the way, complexity in that, in fact, this is an electronic document management with a bunch of forms, you can’t draw it on a piece of paper, since personal meetings are rarely possible. As one of the options, I think to take draw.io and draw diagrams in it, I did it before, I think some other interesting tools may appear, not necessarily online, an offline tool will also work, but it should work in Linux