how do i put an entity tag in this command

i've looked it up and ive checked the error i just dont know how to add an entity tag to this command
this is the command: 
execute as @a[nbt={RootVehicle:{Entity:{id:"#mounts_improved:all_mounts"}}}] run give @s minecraft:apple
it would work if i changed: "#mounts_improved:all_mounts" to: "minecraft:horse"
i want it so you get an apple (to test it) if you're on any animal with that entity tag