Hi,
You're almost there, just need to put a single word Bearer in front of the access token (separated by a space)
When using swagger - after you receive an access token, you can Authorize by clicking Authorize button on the top with Bearer {{----token----}} written into text field
Using API directly, your call should look like this
curl -X GET "https://mspapi.eset.com/api/User/Current" -H "accept: application/json" -H "Authorization: Bearer eyJgbGciOiJSUzI1NiIsImtpZCI6ImU1WTdkMGJEUGtORmFDV094VWlBaUU5MDBDbyIsInR5cCI6IkpXVCIsIng1dCI6ImU1WTdkMGJEUGtORmFDV094VWlBaUU5MDBDbyJ9.e