Domain verification file is being deleted before completion of verification process

I am generating SSL from certifyweb using let’s encrypt. It is deleting text file from acme-challenge directory after creating it before domain verification.

Hi, under normal circumstance the apps built-in http challenge response handler performs the http validation process and the disk based challenge response files are unused.

Are you using the app to get a certificate for an IIS based website or for something else?

Which version are you using?