replicate a postman request in power bi

I use Postman for API requests but my manager has asked me to access it on Power BI. i need a query in m language to get a connection. Thanks a lot!

url: https://backoffice1.aceunion.com/get/cross-border-rates
Authorization: Basic Auth
method: POST
Username: myusername
Password: mypassword
Request body:
{
"from_country": "United Kingdom",
"to_country": "Pakistan",
"method": "Bank",
"amount": "500"
}