POST https://ifas.prod-row.jlrmotor.com/ifas/jlr/tokens/tokensSSO
authorization: Basic YXM6YXNwYXNz
Content-Type: application/json;charset=UTF-8
Host: ifas.prod-row.jlrmotor.com
Connection: Keep-Alive
Accept-Encoding: gzip

json body:
{
    "grant_type": "password",
    "password": "...",
    "username": "..."
}

POST https://sgw.jlr.appcarousel.com/ica/authentication/token
x-ce-app-token: 9VIiAP43qg1GEtLQVdn6tP5xLdD2xy3PKpaNujbPNfw=
x-ce-device-token: aa6a7899-3f16-46d6-87d3-21539353653b <--- maybe the same device_id than original auth method
content-type: application/x-www-form-urlencoded
accept-encoding: gzip
user-agent: okhttp/4.10.0

URLEncoded form body:

grant_type: password
username: ...
password: ...