I have a PHP-Mysql application. I have been following this tutorial to deploy it to heroku.
It asks for give credit card details for ClearDB add on. I do not wish to give up my details. Is there any workaround for this? Or any other free alternative to heroku?
Sooner or later, you will have to give up some card# to register for these online services (Azure, Amazon AWS, etc).
What you can do is buy one of those prepaid cards (MC/VISA) and use that one to give out.
Many providers block prepaid cards due to fraud.
I was able to use one with $.01 for Heroku, C9, AWS, pretty much all of the major companies.
Google Cloud for example.