Authentication error using REST API bearer token

[G H Mahimaanvita]

Hi. I am new to Atlassian.
I want to access the REST API from insomnia/postman like this:

1. url: `https://my-site.atlassian.net/rest/agile/1.0/board`
2. body: 
{
"filterId": 10040,
"name": "scrum board",
"location": {
"projectKeyOrId": "20000",
"type": "project"
},
"type": "scrum"
}
3. In the authorisation tab, I added the bearer token and entered the Atlassian api key. 
I am getting an unauthorised error. 
{
"message": "Client must be authenticated to access this resource.",
"status-code": 401
}

please help

[Nic Brough -Adaptavist-]

Go to the project admin section of each project and read the permission scheme, looking for "administrate project".

The rule in there should say something like "Role: Admins".

Go to the people section of the project and add the group to the role.  (If it's not role:Admins, you'll have to work out what to do from there)