Calling JSON from C#

Is this even possible? Would appreciate feedback.

I am an experienced programmer using Visual Studios and C# but admit I never worked with JSON. What I need to do is write a Windows Form Application (I do not have access to a webserver) that will retrieve data from a datasource. From that datasource I will create a datatable and iterate through approximately 600 records that need to be sent via an API request. The first part is easy but I cannot find any information on how to encapsulate that data into my json code. At this point I do not know if it is possible or not and have exhausted all my resources. My only hope now is that my Topic will interest someone in showing me how to do this. Here is the JSON Request:

{
“account_id”:" 1234",
“api_key”:" Rfti0MJsrVDSUJSrY7t9A27NISzj008v",
“is_comprehensive”:“1”,
“recipients” :
[
{
“external_db_id”:“1201A010120-1”,
“first_name”: “Tom”,
“last_name”:“Smith”,
“address1”:“1234”,
email":"tsmith@gmail.com”,
“cellphone”:“555-555-5555”,
“email_opt_in”:“1”,
“text_opt_in”:“1”,
“recipient_status”:“1”
},
{
“external_db_id”:“091233A33-2”,
“first_name”: “George”,
“last_name”:“Holmes”,
“address1”:“4455”,
email":"George@gmail.com”,
“cellphone”:“9994443303”,
“email_opt_in”:“1”,
“text_opt_in”:“1”,
“recipient_status”:“1”
}
]
}

Thanks
Charles