Acellemail bulk Add Subscriber via api ASAP

Need to fix this part or add a function.
When I send one user's data the API works
{
"EMAIL": "subscriber1example.com",
"FIRST_NAME": "Subscriber1 Fname",
"LAST_NAME": "Subscriber1 Lname"
}

[
{
"EMAIL": "subscriber1example.com",
"FIRST_NAME": "Subscriber1 Fname",
"LAST_NAME": "Subscriber1 Lname"
},
{
"EMAIL": "subscriber2example.com",
"FIRST_NAME": "Subscriber2 Fname",
"LAST_NAME": "Subscriber2 Lname"
}
]

But when I send several I get a response 403

{
"EMAIL": [
"The Email is required"
]
}