Add your own domain response

I’m facing an issue in receiving a mail after running my code for temperature sensor code, it shows the response as follows:
Reading sensor value
Sensor value is: 291
Making request to Mailgun to send an email
Response received from Mailgun is: Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients in Account Settings.

Hi @chayank.racharla,
refer this link, think that would solve your query.

Hey! a small doubt, is it mandatory to put credit card details as I didn’t gave that information

It is not mandatory, but you are restricted to some usage. If you need to create custom domain then you must provide credit card details.