Third parties who are not a pity vote, in the USA , can only arise from the school boards and city halls.
It cannot not be some national or state org who runs candidates for top offices only, asking for funds, and get a few votes
I think that local process to build options is broke right now, because grassroots are stalled at the neighborhoods, except for a few places in big cities.
It’s broke but it’s not dead
If you want third party, then run or support school board candidates, dog catchers, sheriffs; and then look to the next county for like minded folks. Someday it could be a coalition to change state politics