MS Dynamics 365 Business Central. API POST, PATCH, DELETE does not work

We have installed on our server MS Dynamics 365 Business Central (I don't know how to view currently installed version). We are using oData v4 protocol for our requests.

Task

We need to make API calls to this system from PHP

Issue

It's impossible to make POST, PATCH, DELETE requests when GET request works well.

GET

Request:

GET d365bc.vendor.com:7058/.../Customer

Response

{
    "@odata.context": "">d365bc.vendor.com:7058/.../$metadata,
    "value": [
        {
            "@odata.etag": "W/\"JzQ0O29EcmJmcGs4V3NRMHlEQ0Fxa0JxL1N0bi9xZjY5UDFQakZ0U2tBUGU1Kzg9MTswMDsn\"",
            "No": "01121212",
            "Name": "Spotsmeyer's Furnishings",
            "Responsibility_Center": "",
            "Location_Code": "YELLOW",
            "Post_Code": "US-FL 37125",
            "Country_Region_Code": "US",
            "Phone_No": "",
            "IC_Partner_Code": "",
            "Contact": "Mr. Mike Nash",
            "Salesperson_Code": "JR",
            "Customer_Posting_Group": "FOREIGN",
            "Gen_Bus_Posting_Group": "EXPORT",
            "VAT_Bus_Posting_Group": "EXPORT",
            "Customer_Price_Group": "",
            "Customer_Disc_Group": "",
            "Payment_Terms_Code": "1M(8D)",
            "Reminder_Terms_Code": "FOREIGN",
            "Fin_Charge_Terms_Code": "2.0 FOR.",
            "Currency_Code": "USD",
            "Language_Code": "ENU",
            "Search_Name": "SPOTSMEYER'S FURNISHINGS",
            "Credit_Limit_LCY": 0,
            "Blocked": " ",
            "Privacy_Blocked": false,
            "Last_Date_Modified": "2020-06-18",
            "Application_Method": "Manual",
            "Combine_Shipments": true,
            "Reserve": "Optional",
            "Shipping_Advice": "Partial",
            "Shipping_Agent_Code": "",
            "Base_Calendar_Code": "",
            "Balance_LCY": 0,
            "Balance_Due_LCY": 0,
            "Sales_LCY": 0,
            "Global_Dimension_1_Filter": "",
            "Global_Dimension_2_Filter": "",
            "Currency_Filter": "",
            "Date_Filter": "..11/13/20"
        },
        {
            "@odata.etag": "W/\"JzQ0O08vNlVHSWVaZ1FGeG42d2JOa3k4Qm5uVHlkSGYzNk1ES2V5Y2E2S3hiekU9MTswMDsn\"",
            "No": "01445544",
            "Name": "Progressive Home Furnishings",
            "Responsibility_Center": "",
            "Location_Code": "YELLOW",
            "Post_Code": "US-IL 61236",
            "Country_Region_Code": "US",
            "Phone_No": "",
            "IC_Partner_Code": "",
            "Contact": "Mr. Scott Mitchell",
            "Salesperson_Code": "JR",
            "Customer_Posting_Group": "FOREIGN",
            "Gen_Bus_Posting_Group": "EXPORT",
            "VAT_Bus_Posting_Group": "EXPORT",
            "Customer_Price_Group": "",
            "Customer_Disc_Group": "RETAIL",
            "Payment_Terms_Code": "14 DAYS",
            "Reminder_Terms_Code": "FOREIGN",
            "Fin_Charge_Terms_Code": "2.0 FOR.",
            "Currency_Code": "USD",
            "Language_Code": "ENU",
            "Search_Name": "PROGRESSIVE HOME FURNISHINGS",
            "Credit_Limit_LCY": 0,
            "Blocked": " ",
            "Privacy_Blocked": false,
            "Last_Date_Modified": "2018-09-19",
            "Application_Method": "Manual",
            "Combine_Shipments": true,
            "Reserve": "Optional",
            "Shipping_Advice": "Partial",
            "Shipping_Agent_Code": "",
            "Base_Calendar_Code": "",
            "Balance_LCY": 1499.03,
            "Balance_Due_LCY": 1499.03,
            "Sales_LCY": 1499.03,
            "Global_Dimension_1_Filter": "",
            "Global_Dimension_2_Filter": "",
            "Currency_Filter": "",
            "Date_Filter": "..11/13/20"
        },

DELETE

DELETE https://d365bc.vendor.com:7058/attain/ODataV4/Company('{{company}}')/Customer(No='01121212')

{
    "error": {
        "code": "BadRequest",
        "message": "Entity does not support delete."
    }
}

I'm not sure what is the correct syntax for the Create (POST) or Update (Patch) For the POST request I tried to copy existing value (taken from GET) and put it into the body. I'm getting following response:

{
    "error": {
        "code": "BadRequest_MethodNotAllowed",
        "message": "Entity does not support insert."
    }
}

Sometimes if I make absolutely wrong request I'm getting following response:

{
    "error": {
        "code": "BadRequest_MethodNotAllowed",
        "message": "'POST' requests for 'Customer' of EdmType 'Entity' are not allowed within Microsoft Dynamics 365 Business Central OData web services."
    }
}

I'm unable to apply CUD operations for Customers, ProductItems. However for orders it works.

Existing Privileges

If I follow

Setup & Extensions / Manual Setup / Users / [Select User]

In the permissions section, there are too many assigned privileges. Among them, there is a SUPER privileges item. As I know all names are custom there. Here is the screenshot of the assigned privileges.