Sharepoint Rest API - issues GetFileByServerRelativeFilePath- File content retrieve issue Postman

Hi Team,

I am using rest apis to get sharepoint file content.  While trying to fetch the file content Iam facing issues using postman.
The authentication etc is right using Azure AD application only authentication.
Rest api below
<org>details and api
GetFileByServerRelativePath('relative path and file name

Response 
 Cannot deserialize data for type Microsoft SharePoint SPResourcePath

Tried both Relative path and URL  if I add Get File By Server Relative url then I get the below error Which is wrong

The file File path doesnot exist