SMS Custom Provider Token

Hi, I have a question regarding token/API key when configuring a new API Credentials for an SMS custom provider.

Here the cURL for sending an SMS (no neccesary to create a token for sending)

And then I have this cURL for token:

When I go to create the API credential, I have the API KEY option, what should I paste here, in Name = "Bearer" and in API token, the api_key? (based on first image cURL)

or should I generate a new token with the jwt option (2nd image cURL)

and then adding the authentication parameter in the header?

Here the custom payload I need to paste:

{
"message": "This is test and \n this is a new line",
"to": "+111111",
"bypass_optout": True,
"sender_id": "SMSto",
"callback_url": "https://example.com/callback/handler"
}

I've tried everything and I have failed authentication when trying to send Verification SMS 

I'm completly lost about this SMS configuration. Your help will be very valuable.

Thanks!