const options = {method: 'POST', headers: {cookie: 'session='}};

fetch('https://api.example.com/v1/regions/global/notifications/inbox/read-all', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.example.com/v1/regions/global/notifications/inbox/read-all"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("cookie", "session=")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

curl --request POST \
  --url https://api.example.com/v1/regions/global/notifications/inbox/read-all \
  --cookie session=

import requests

url = "https://api.example.com/v1/regions/global/notifications/inbox/read-all"

headers = {"cookie": "session="}

response = requests.post(url, headers=headers)

print(response.text)

{
  "success": true,
  "data": {
    "markedCount": 123
  },
  "meta": {}
}