I am looking for retrieving Fingerprint data to be sent to server backend. My application is used by sales team and whenever there is new customer, the sales will ask custom
Neither, the fingerprint image nor its features are accessible by the API. From Android website I quote:
Thus, raw images and processed fingerprint features must not be passed in untrusted memory. All such biometric data needs to be secured within sensor hardware or trusted memory. (Memory inside the TEE is considered as trusted memory; memory outside the TEE is considered untrusted.)
I seriously doubt you can get raw fingerprint data because it is used as an authentication method.
In the same way that you can't retrieve the device password, you won't be able to get fingerprint data. It would be a significant security risk to do so.
As mentioned before, the Fingerprint API's won't allow you access to the raw data.
But there is a different solution. Don't use the Fingerprint scanner. Instead use the camera.