I don't know programs and mods...
but i think i figured out how to solve...
just do as i say, and tell me if there is something else...

go Stellaris/mod/1903626314/common/traits.
make .txt file named, "02_species_trats_basic_characteristics".
write the following there and save the file,

trait_hive_mind = {
cost = 0
sorting_priority = 20

initial = no
randomized = no
modification = no
forced_happiness = yes

modifier = {}

leader_age_min = 10
leader_age_max = 20

allowed_archetypes = { BIOLOGICAL PLANTOID LITHOID }
ai_weight = {
weight = 0
}

icon = "gfx/interface/icons/traits/leader_traits/leader_trait_ruler_hive_mind.dds"
}

Play Hive minded Plantoids.