Okay I've pulling my hair out because I cannot for the life of me figure out how to execute a command if an entity has a tag. This seems like such a basic function yet I am too stupid to figure it out.

Below are two sets of commands written almost exactly except one uses type=chicken and one uses tag=test

# Failed Attempts to teleport
execute as @e[tag=test] run teleport ~ -500 ~
teleport @e[tag=test] ~ ~-500 ~
execute if entity @e[tag=test] run tp @e[tag=test] ~ ~-500 ~
tp @e[tag=test] @s

# Teleportation works
execute as @e[type=chicken] run teleport ~ -500 ~
teleport @e[type=chicken] ~ ~-500 ~
execute if entity @e[type=chicken] run tp @e[type=chicken] ~ ~-500 ~
tp @e[type=chicken] @s

All I want to do is teleport a chicken into the void if it has the tag of test.