sending messages via LinkedIn API

Question

Good afternoon, I'm trying to make a PHP application that sends messages to Linkidin. From the source data there is a username and password and a user ID to which you need to send ACoAAD-VT8sBOkDLIxA0177uoxeP081m1Mvt29c. If anyone has had experience writing such applications in other languages, please share.

I also found out that there is a post overgrown with

https://www.linkedin.com/voyager/api/voyagerMessagingDashMessengerMessages?action=createMessage 

{
    "message": {
        "body": {
            "attributes": [],
            "text": "р"
        },
        "renderContentUnions": [],
        "conversationUrn": "urn:li:msg_conversation:(urn:li:fsd_profile:ACoAAD-VT8sBOkDLIxA0177uoxeP081m1Mvt29c,2-OWQyYWVlNTgtM2VjNy00NWY5LWJhYWQtYjRhODY3ZDU0NmVhXzAxMw==)",
        "originToken": "1afad75e-ed34-4dd7-a7ce-fd4999937da7"
    },
    "mailboxUrn": "urn:li:fsd_profile:ACoAAD-VT8sBOkDLIxA0177uoxeP081m1Mvt29c",
    "trackingId": "\u001aú×^í4MקÎýI}§",
    "dedupeByClientGeneratedToken": false
}

but it’s not clear how to bypass authorization