Team script, having errors! Can someone please help?

I've recently been trying to script a team thing for my group, but every time I test it with my friends, we always are on random teams that are not correct.

Yes, the people I test with are in the stuff required for this to work.

Can someone help me fix this?

plr = game:GetService("Players")
teams = game:GetService("Teams")
name = plr.Name

if plr:GetRankInGroup(1112405) <= 13 then
    teams == "TEST"
end
if plr:GetRankInGroup(1112405) >= 12 then
    teams == "DTRA"
end
if plr:GetRankInGroup(1112405) == 0 then
    teams == "Visitors"
end

The error is on this part:

if plr:GetRankInGroup(1112405) <= 13 then
    teams == "TEST"
end