How to identify type of 3-way switch wiring
Actually since there are no white wires on the 3-ways, this gets simple.
The black and red wires that DO go to the 3-ways are part of cables.  Note which cables they are.  It matters.
Almost certainly, two cables are involved, and the 2 white wires in those cables are connected to each other.
As long as that's so, you can add the smart switch's white wire to those two white wires (might be more than 2).
Do keep in mind that with smart switches, often, the smart switch's design will dictate where it must go.  So don't just go &quot;Imma puttin it there&quot; and try to force it to work. Actually read the instructions and think about what you're doing.