If you do not want to collect credit card information during sign up, you can build a form on your website to collect the customer's name and email address and create the trial subscription.
I've attached a sample sign up page with the code to create trial subscriptions without a credit card. Similarly, you can build your own form.
In the attachment, if you browse to "trial_signup > chargebee_js > signup.html", you will see a code similar to what I've pasted below.
The changes you need to make for this sample sign up form to work(indicated with arrows above) are:
1. Your ChargeBee site name (only the sub-domain name).
2. A publishable API key. You can create one under Settings > API keys > Add API Key.
3. Your trial plan ID. You will find this when you open your trial plan under "Product Catalog".
When creating a publishable API key, please ensure that you check the option "Use From Browser" as shown below:
And also select the option "Publishable API Key".
Related post: https://support.chargebee.com/discussions/topics/304854