RENDER is asking for payment info even on Static Site hosting

I am a new user of Render. whenever i tried to host a static boostrap template on render , it is asking for credit card payment info to be added. why?
Render has allowed to host static sites for free as mentioned in the website but it not hosting sites without adding credit card payment info. kindly let me know what is the problem?
and how to resolve this issue?
i am waiting for your kind and swift reply.thanks

There could be a number of reasons - we use credit cards as a verification method. Also, if you use more than 100Gb of bandwidth then we charge for the extra bandwidth consumed.