I need to pass .PFX file through API call with postman (As Base64File)

My question:

Hello everyone,
I am facing an issue by attaching a file to the API call through Postman. The file is a “Wildcard (.PFX)” which can add subdomains. So, in my payload I have to send following data
{
** “DomainName”: “string”,**
** “SubDomain”: “string”,**
** “CertificatePassword”: “string”,**
** “WebsiteId”: “string”, **
** “Base64File”: “string”**
}

What I did was going to Body → Raw data as follows
Gave the name to KEY as basefile
attached the encoded PFX text file to the value.
Then I have pass the name of the KEY to payload as follows.
** “Base64File”: “{{basefile}}”**
Then I get following error message.

"Message": "The request entity’s media type ‘multipart/form-data’ is not supported for this resource."

Screenshot (1167)

These are details of the header

I’ve already tried:

I tried to attach the pure PFX file without converting. But it didn’t work.

I would really appreciate if anyone could help me on this issue.

Best Regards